ABV  Alcohol by volume. The % of alcohol in a wine.
Acetaldehyde Organic chemical molecule produced as a by-product of fermentation, and as a result of oxidation of the alcohol to acetaldehyde. It's needed for the special aroma of oxidized wines like sherry and Madeira, but too much spoils the flavor of all wines. 
Acetaldehyde A compound produced by fermentation and oxidation exhibiting fruity, chocolate, pumpkin type aromas. Acetaldehyde has been shown to assist in the stabilization of wine color.
Acetic The vinegar-like off odor of acetic acid. Acetic acid can be formed by the action of the bacteria acetobacter. These wines often have a sweet, slightly vinegary odor and a sharp, tart flavor.  
Acetification  The formation of acetic acid from alcohol - what we'd call the conversion of wine to vinegar by bacterial infection. To avoid acetification, fermentation vessels should be sterilized and kept full. You can prevent infection by Acetobacter, responsible for the conversion, by using good hygiene and sterilization procedures, but once a wine is infected you won't be able to save it. Don't use any equipment or vessels to make your wine which may have held vinegar!
Acetobacter: A group of bacteria that oxidatively convert wine to vinegar (ethanol into acetic acid) through an aerobic (oxygen present) fermentation.
Acid  The acids in a wine must provide sharpness and flavor; they also ensure the yeast has an environment suitable for fermentation. There are three main types of acid: citric, the acid of citrus fruits; tartaric, the acid of grapes and other fruits; and malic acid, the acid chiefly of apples. A good blend for use in home winemaking is 50% tartaric, 30% malic and 20% citric.
ACID BLEND  Mixture of the tartaric, malic and citric acids. Used in wines needing additional acid. Test the acid level before adding any type of acids.
Acid blend: A generic name for any commercially available blend of acids (usually citric, tartaric, and possibly malic) sold for the acidification of homemade wines.
Acidification The addition of acid (usually tartaric) during fermentation, Frequently necessary in hot climates where grapes tend to over ripen and become deficient in acidity, thereby losing freshness.
Acidity Too much acid makes a wine sharp or acidic and leaves a sour or sharp taste on the palate; too little makes it flabby or bland. You can test for acid levels using a pH meter, titration or both. Otherwise you can just follow a recipe. It's important to have the right levels of acidity in a must so fermentation can proceed correctly and the finished wine will be balanced and enjoyable.
Acidity Tartness, the taste of natural fruit acids (tartaric, citric, malic or lactic) in wine. Minute traces of other acids are all found in wine. There are two measures of acidity used in winemaking; see pH and Titratable acidity.
ACIDITY IN WINES - DESIRABLE  WINE ACIDITY Dry white table .65-.75% Dry red table .60-.70 Sweet white table .70-.85 Semi-sweet table .65-.80 Sherriers .50-.60 Sparkling same as similar table wine Ports same as semi-sweet table wine Fruit same as similar grape table wine
Acidity Malic  A measure of a tangy, zesty type of acid (akin to green apples) found in many white wines. Attributed with giving a wine "verve" or "crispness," in excess it can be quite harsh and aggressive. Found in all wines that have not gone through malolactic fermentation.
Acidity Total  A sum of the fixed (normal organic fruit acids) and volatile acids (those which can be removed by distillation) in wine. Total Acidity directly effects the color and flavor of wine and, depending on the style of the wine, is sought in a perfect balance with the sweet and bitter sensations of other components. Too much acidity makes wine tart and sharp; too little makes wines flat, flabby and uninteresting. Proper acidity in wine is what makes it refreshing and an ideal accompaniment to food.
Acidity Volatile  A technical term for a the portion of total acidity that is volatile (can evaporate) representing mainly acetic acid, akin to vinegar. Generally found at .3 g/l to .5 g/l. In excess (.8 g/l), it is identifiable as a negative vinegar flavor.
Activated Yeast A dried yeast which has been cultivated using a Yeast Starter. Once activated, the yeast is ready to ferment the must. Activation is essentially a process of developing a thriving yeast colony with enough yeast cells to ferment a must.
Aeration: The process of incorporating air into a wine, must, or juice. Usually through splashing while racking, sparging with air, or simply by stirring a container very vigorously. This is sometimes done to "blow off" undesirable aromas such as hydrogen sulfide or to give an initial dose of oxygen to a fermentation just getting under way.
Aerobic fermentation  The first part of the fermentation, conducted in the presence of air, in a tank, fermentation vat, pail or other such vessel, during which yeast builds up a strong colony of cells.
Aftertaste The lingering residue of flavor after you have swallowed a wine, which should impart some memory of the wine's essential character - fruity, dry, sweet, etc. 
Aging The process of maturing a wine, in anaerobic conditions, so that the chemical reactions essential for the development of full flavor and aroma can proceed to completion. The chief reaction is the formation of volatile esters by reaction of wine acids and alcohol to produce esters, aromatic molecules which give a wine its bouquet. In additions, tannin will react with wine acids and precipitate out. The reactions proceed more slowly in bottle than cask.
Aggressive A term used to describe a wine with harsh flavors, often the result of too much tannin or acid.
Air-lock (fermentation lock, air trap, bubbler)  A glass or plastic device which excludes external air from the fermentation vessel, but allows carbon dioxide to escape.  
Alcohol The compound responsible for the formation of character and flavor, not to mention the intoxication of the drinker, in a wine, is a 5 carbon atom chain alcohol also known as ethanol or ethyl alcohol. Other alcohols such as propanol or butanol with more carbon atoms form during fermentation, and contribute to the flavor and body of wine. Methanol, or methyl alcohol, is extremely poisonous.
Alcohol In general usage, alcohol (from Arabic al-khwl الكحول, or al-ghawl الغول) refers almost always to ethanol, also known as grain alcohol, and often to any beverage that contains ethanol (see alcoholic beverage). This sense underlies the term alcoholism (addiction to alcohol). Other forms of alcohol are usually described with a clarifying adjective, as in isopropyl alcohol or by the suffix -ol, as in isopropanol. 
Alcohol In chemistry, alcohol is a more general term, applied to any organic compound in which a hydroxyl group (-OH) is bound to a carbon atom, which in turn is bound to other hydrogen and/or carbon atoms. The general formula for a simple alcohol containing no rings is CnH2n+1OH. 
Alcohol Content A natural result of fermentation, when the grape skins are broken by "crushing" and the yeast from the outside of the grape comes into contact with and metabolizes the sugar from inside the grape and transforms it into alcohol, carbon dioxide and heat. Content by volume ranges between 9% and 15% for table wines, with most falling between 11% and 13%. An important measure in determining the body of a wine.
Alcohols Alcohols are the family of compounds that contain one or more hydroxyl (-OH) groups. Alcohols are represented by the general formula R-OH. Alcohols are important in organic chemistry because they can be converted to and from many other types of compounds. Reactions with alcohols fall into two different categories. Reactions can cleave the R-O bond or they can cleave the O-H bond.
Ameliorate To add a substance to a wine must or finished wine to modify its flavor and quality. For example: adding water to a must, or concentrated grape juice to sweeten a finished wine.
American Oak  Oak of the genus/species Quercus alba harvested in the United States
Amylase An enzyme that converts starch to fermentable compounds.
Anaerobic fermentation  The second part of the fermentation, conducted under air-lock and in the absence of oxygen, during which most of the alcohol is formed.
Antioxidant Anything designed to stop a wine oxidizing and losing quality of flavor at any stage of its preparation. Sulfur dioxide is the best antioxidant.
Antioxidant: Compound that retards oxidation and slows its effects in wine (browning, sherry-like aromas). Sulfur dioxide, SO2, is the most widely used winemaking antioxidant. It also serves as an antimicrobial agent.
Anthocyanins The pigment compounds responsible for the color of red grapes 
Appellation From the French, a geographic designation for a grape growing region. An appellation can be quite large on the order of a State or Province or quite small on the order of a valley or even a particular chateau. Appellations are typically approved by governmental agencies who also regulate the manner in which an appellation name can be used for a particular wine blend. As an example for a wine to carry the Napa Valley appellation name on its label, 85% of that wine must come from grapes grown within the Napa Valley appellation. 
Aroma The fragrance of a wine due to its original ingredients. Compare with bouquet.
ASCORBIC ACID  Used as an antioxidant or anti browning agent. Used in making apple wine. This is not vitamin C tablets.
Ascorbic Acid  This reduces oxidation in bottled wine when added just prior to bottling (not effective for bulk storage). Use: 1 teaspoon per 6 US gallons of wine. Also can be used to prevent apple cider from browning before fermentation.
Astringency A taste and a mouthfeel that seems constricting or puckering - hard to describe, but easy to recognize. Due mostly to tannins in a wine, it tends to mellow with age as the tannins precipitate out. It is not the same as bitterness.
Astringency: The dry, puckery sensation caused by tannin in wine. The tannins actually denature the salivary proteins, causing a rough "sandpapery" feel in the mouth.
Austere High-acid and typically young wines.
Autolysis Breakdown of dead yeast cells in a wine, giving a rich flavor, structure and body to wines like champagne, and those made from chardonnay or sauvignon blanc.  See sur Lie
Auto Siphon With the FermTech Auto Siphon, siphoning has become a snap and nary a drop of wine is splashed during racking. Just attach some tubing, insert one end into the carboy, and give the pump handle a couple of strokes on the other end. Within seconds, a siphon is started and wine begins moving to the other vessel. Even experienced winemakers prefer this siphoning method because it's more sanitary than the old-fashioned way!
AVA (American Viticultural Area) A system implemented in 1983 created to identify the origin of US wines along the same lines as the French Appellation d'Origine Controlee system. An AVA is a geographic area only and has no impact on the variety of grapes grown or the wine making methods utilized.
Backbone Wines with good acidity and tannin structure.
Baked The caramel odor in sweet wines, such as Madeira, that have been heated at high temperatures. These wines often have a warm, earthy aroma. Also wines from over-ripe grapes
Balance A wine is balanced when it has all the ingredients present in the correct proportion: acid, fruit, tannin, sugar, alcohol. Proper balance allows a wine’s bouquet to come forward without being overpowered by alcohol or off flavours.
Balling A scale for denoting the density of liquid in terms of specific gravity. Balling and Brix are identical scales used to estimate sugar content of the must
Barnyard A smell in wine similar to that of a barnyard, this can be caused by unsanitary winemaking conditions or by a yeast cell called Brettanomyces
Barrel Most of the world's greatest wines are at least partially aged in barrels, usually made from oak. A barrique is the standard Bordeaux barrel, holding 225 liters or the equivalent of about 300 bottles of wine. But casks may be as large as 100 hectoliters (i.e., 10,000 liters) or more. Also called a Cask
Barrel Fermentation The process of fermenting grape juice/wine in small barrels instead of large vats. Barrels are usually made from oak and are approximately 60 gallons in size, although larger and smaller sizes are available. Fermentation in oak imparts a variety of attractive aromas and flavors and often results in a richer creamier style wine
Barrique A Bordelais term for a 225 litre barrel (almost 60 gallons)  
Base The original ingredients form which a wine is made.
bâtonnage The French term for stirring the lees back up into the wine a stick to increase flavor extraction. 
Baumé A term to measure Specific Gravity, which indicates the sugar content of unfermented grape juice. One degree baumé is equivalent to 1.8 degrees Brix. 1 degree baumé ferments out to approximately 1% alcohol.
B-Brite  This compound is used to sanitize winemaking equipment. It cleans with active oxygen, and does not contain chlorine or bisulfite. Effectively removes fermentation residues.
B-T-F This concentrated iodine-based solution sanitizes winemaking equipment. Use: Dilute with cool or lukewarm water to obtain desired iodine concentration. Adding 0.3 oz in 3 gallons of water creates 12.5 ppm, while adding 0.6 oz in 3 gallons of water makes a solution of 25 ppm. Immerse items for 1 to 2 minutes; allow sanitized items to drain well or air dry. CAUTION: Never add to hot water; might stain clothes. Winemaking equipment must be cleansed separately beforehand, since B-T-F is not rated as a cleanser.
BENTONITE  Use: Dissolve one tablespoon of B-Brite powder in one gallon of water to create a sanitizing solution. Sanitize winemaking equipment for at least one minute, then rinse with clear tap water. Discard solution after use.
Bentonite  This is powdered clay that is used as a fining agent to clarify wine. Caution: If too much is used, your wine will have an earthy flavor.
Bentonite  Use: Bentonite should be made up 24 hours before adding to wine. For a standard six gallon kit, add no more than 2 tablespoons of bentonite to 1/2 cup warm water; mix or shake well. The manufacturer recommends mixing 2 1/2 teaspoons into 2 1/2 cups boiling water. Mix really well, allow to cool, and add to wine. Some folks we know use a blender!
Bentonite  A powdery clay found in Wyoming and Germany that is used as a fining agent to clarify wine. 
Bite   The astringency of a wine, produced by tannin. Without sufficient tannin, a wine may taste flat and insipid.  
Bitterness A sense of taste in a wine which is not pleasant. Not the same as astringency, which is felt in the mouth rather than tasted. Bitterness is most often associated with polyphenolic compounds, especially tannin, but high sulfate (not sulfite) content can also produce bitterness. Bitterness can 
Bocksin  This solution of silicium dioxide removes H2S (hydrogen sulfide) odors and related off-flavors in wine. An indication of H2S is the smell of rotten eggs. Use: Add 15 ml (0.5 oz) per 10 liters of wine. Stir thoroughly and wait 24 hours. Rack without disturbing the sediment. It is recommended to filter the wine after treatment. If the wine becomes cloudy, treat with finings.
Botrytis Botrytis is a double-edged sword and it can either destroy you or be to your benefit. It is actually a fungus which tends to attack grapes and which may eliminate a vineyard. It is also a good thing sometimes, especially when it causes noble rot instead of destroying the grape crop. Noble rot takes water away from the grapes and this leaves behind a sugary juice which makes sweet and great tasting wine.
Bottles These come in many sizes:  A Magnum is equivalent to  2 standard bottles (1.5 litres); a Double Magnum is 3 litres; Jerobaom is 3 litres of sparkling wine; Methusalah, 6 litres; and a Nebuchadnezzar is 15 litres of sparkling wine!
Bottle sickness Immediately after bottling a wine may seem unpalatable, bland or flat. This blandness or flatness will last for only a short period of time. 
Bottle stink An unpleasant aroma which may be apparent after opening an aged bottle of wine. It soon disperses, leaving the true aroma and bouquet of the wine.
Blending The process of mixing wines with differing qualities so that their faults or deficiencies cancel each other out.
Body  The body of wine refers to the sense of fullness one gets when drinking it. The opposite is "thin", which means a wine tastes thin and watery.  A wine of full body will contain more glycerol  and higher alcohols than a thin wine.
Botrytis cinerea/Noble rot A fungus that causes results in shriveled, concentrated grapes. It has been adapted as a desireable condition for wines such as French Sauternes, German Trockenbeerenauslese, and Hungarian Tokaji. 
Bottle shock A temporary period immediately following bottling during which the wine is flat, and less palatable
Bouquet   The aroma or "nose" of a wine which develops during storage in bulk containers or bottles. Produced by slow chemical reactions between acids and alcohol in the wine. The bouquet may rapidly dissipate revealing the inherent wine fragrance (aroma). 
Breathing Allowing a wine to mix with the air. Aeration occurs by pouring the wine into a larger container, such as a decanter or large wineglass. Breathing can be beneficial for many red wines and also for some young white wines. Chemically, breathing enables oxygen to mix with the wine, which hastens the aging process. If a wine stands open for more than 12 hours, it will begin to turn to vinegar as the oxygen continues to work. Whether to let a wine breathe before serving depends on the wine. Contrary to popular belief, it is not always beneficial to let older wines breathe prior to drinking, as this can cause them to "turn" - or go bad - before dinner is over.
Brettanomyces/Brett A yeast that imparts strong aromas such as horsey, barnyard, bandaid, medicinal, leather and/or spice into wine 
Brilliant  A clear and bright - as opposed to cloudy - appearance. 
BRIX  In simple form, brix is a hydrometer scale used in measuring the sugar content of a solution at a given temperature. Starting brix when making wine is about 21 degrees depending on wine type.
Brix Brix - a measure of sugar content or concentration in the grape juice at harvest. At normal fruit maturity, growth ceases and physiological accumulation of sugar ceases at about 25 Brix; further increases are the result of water loss as the grape develops into a raisin, which is only desirable in late harvest dessert wines. Desirable range for a table wine is between 19.5 and 23.5 in free-run grape juice before fermentation. Brix, along with weather and acidity, is one of the major determining factors in the Date of Harvest.
Brix A scale for denoting the density of liquid in terms of specific gravity. Brix and Balling are identical scales used to estimate sugar content of the must. 
Bulk aging: As opposed to aging wine in its final bottles, the term "bulk aging" is used to describe aging that might be done after fermentation but before bottling. Typically for home winemakers, this maturation occurs in five-gallon carboys or small oak casks.
Bung A stopper used to seal a cask, keg or barrel. 
CALCIUM CARBONATE (Precipitated Chalk)  Used to reduce acid in wines or must. Reacts more with tartaric acid. Does not cold stabilize well. May leave a taste in the wine. Generally not suggested for use if alternates can be used. 3.8 gr. per gal, 19 gr. to 5 gal, 3 tsp. to 5 gal.
Calcium Carbonate  This chemical is basic; in other words, it lowers the acidity of your wine to within your targeted range. Calcium carbonate is often used in place of adding water to achieve a more basic wine, since adding water will dilute your wine. Use: 1/2 oz reduces acidity by 1 ppt in 6 US gallons of wine. Be sure to perform an acid test so you don't overshoot your desired mark.
Campden tablets: A convenient way of delivering sulfites to wine. One tablet contains one-half gram of potassium or sodium metabisulfite.
Campden Tablets   Small tablets of compressed sodium or potassium (preferred) metabisulphite powder which are used to make up sterilizing solution or to protect a wine against oxidation or infection during storage.  Easy to use. Usually one or two crushed tablets per gallon to sterilize must (wait 24 hours before adding yeast). Helps prevent oxidation. Can use one crushed tablet per gallon at each racking. Always disolve before stirring in must or wine. 
Canopy The shoots, and leaves of the grapevine during the growing season
Cap Fruit skins, stems, and pulp that float to the surface during a fermentation. It is essential to "punch down" the cap into the wine during a red wine fermentation to extract valuable tannins and colored compounds as well as to discourage the proliferation of spoilage organisms in the cap.
Capsule  Not used on many wine bottles in modern times, the capsule was a foil or lead covering for the cork, often used to keep rats or mice from chewing their way into the cork. Home winemaking shops sell a heat shrink type that works good.  Many home wine makers use them to dress up their finished bottles.
Carbon Dioxide   Odourless, harmless gas produced during fermentation by the action of yeast on sugar dissolved in the must. Clearing The natural process by which sediment drops out of a wine after fermentation, to form a deposit of lees and leave the wine clear.  
CARBON DIOXIDE (CO2)  Carbon dioxide is a gas produced by the process of yeast converting sugar into alcohol. As the CO2 is produced, it rests on the surface of the wine helping to reduce oxygen from getting into the wine. CO2 is also used to 'top off' wine, or adding CO2 to the top of the carboy to replace oxygen that may have gotten into the carboy. CO2 is also used by some winemakers to move the wine when racking, or to push the wine when filtering. 
Carboy: A glass container that looks like an office water-cooler bottle or a large jug. Carboys usually come in 2.8, 3.0, 5.0 & 6.5 gallon volumes and are used for fermenting juice, carrying out secondary fermentations, and for long-term storage.
Cellar A storage area for wine, not necessarily underground. A cellar is the best area to keep wines for aging. Ideal conditions are darkness, controlled cool temperature, and high humidity. Bottles should be stored on their sides to keep the corks from drying out.
Chaptalize To add sugar to a must or wine. 
Character  That which makes a wine distinctive. A region's winemaking tradition, soils, and grape varieties combine to produce a wine's character.
Chewy Full-bodied, rich, tannic wines 
Chill proofing  AKA cold stabilizing Deliberately exposing wines to very cold temperatures prior to bottling to, primarily, precipitate any tartrate crystals that might come out of solution later. It is seen as more of a quality-control step than a necessity for home winemakers.
CITRIC ACID A colorless acid found in all citrus fruit, pineapples, and in lesser amounts in several other fruit.  Helps prevent iron hazes. 1 tsp=4.3 gr.
Clarification The process of removing cloudiness in the wine by filtration and/or fining.
Clarity The clearness of the wine.
Clean A wine with no off smells or flavors.
Clearing: The natural settling-out of small particulates and suspended matter in finished wine over time. The material that settles out to the bottom of the container is called the "lees."
Clone A group of genetically identical, asexually propagated plants that can be traced back to a single plant.  Grape varietals  are clones.
Cloudy The opposite of clear or brilliant. Possibly the result of sediment being stirred up during transportation.
Cloying Overly sweet, and lacking the correct amount of acidity to give the wine balance.
Cold soak Exposing the must to a brief period (1-3 days) of cold temperatures prior to fermentation to extract water soluble compounds.  See also Maceration and extended Maceration.
COLD STABILIZATION  Cold stabilizing reduces the acid level, and will reduce or eliminate the crystals forming when cooling wine in the refrigerator. Keeping wine in a 32 - 35 degree temperature for two weeks will drop out tartaric acid in the form of crystals reducing the acid level of the wine. Keep wine dark.  
Color Intensity  The amount of a wine's color, most often used in red wines. Ranges from 300 for a very light red wine to over 1,000 for a very intense wine like Cabernet Sauvignon. An average Brunello, for example, would be about 600 or 700. May also be expressed without the 00's - e.g., 5 instead of 500.
Complexity A balanced, rich, nuanced wine demonstrating finesse. 
COPPER SULFATE Used to remove hydrogen sulfite (H2S) from wine. Use when fermentation is finished, but only as a last resort if racking wine does not eliminate the problem.  
Corked A moldy odor and flavor from fungus-infected cork attributed to small amounts of trichloroanisole (TCA) in the wine.
Corked An expression meaning the wine has gone bad. Implies an unpleasant, musty, moldy smell imparted by a flawed cork. Cork can contain bacteria that will cause "off" flavors in the wine. Quality cork manufacturers bleach and process corks to minimize the chance of a bottle being "corked." Unfortunately, almost one out of twelve bottles will have some off, corky flavors. It is for this reason that alternative wine bottle closures have been tested in recent years, but the use of non-cork closures has been resisted by traditionalists. Any closure that seals the bottle airtight is a perfect one for wine. Contrary to popular belief, cork does not - or should not - let air into a wine bottle over time. It is intended to create an airtight seal. 
CREAM OF TARTER See POTASSIUM BITARTRATE and COLD STABILIZATION 
Crusher; crusher-stemmer A machine that breaks open grapes, it usually de-stems them as well. 
Cuvée: French winemaking term relating to the specially blended base white wine that will be made to undergo a secondary fermentation in the production of sparkling wines. It also refers to a blend of different wines in general.
Cuvée 1 Cuvée (or Cuvee on some English language labels) is a French wine term derived from cuve, meaning vat or tank.[1][2] The term cuvée is used with several different meanings, more or less based on the concept of a tank of wine put to some purpose:
Cuvée 2 · On wine labels to denote wine of a specific blend or batch. 
Cuvée 3 · In some regions, the term cuvée is used to specifically indicate a blend, i.e., a wine produced from a mixture of several grape varieties, rather than a varietal wine. This is especially true outside of France. 
Cuvée 4 · In Champagne and sometimes in other regions producing sparkling wines by the traditional method, the cuvée also refers to the best grape juice from gentle pressing of the grapes. 
Decant  To gently pour clear wine from the bottle into a serving container (decanter or carafe) leaving the bottle sediments behind
Degrees Brix: The amount of sugar in a wine, usually measured by a hydrometer, which is a floating instrument that determines the density of solution. Based on a system calibrated to the density of water, the pre-fermentation degrees Brix of most table wines are between 22 and 24, meaning 22 to 24 percent sugar (really the percentage of total soluble solids, including unfermentable sugars). Knowing the Brix helps predict the final alcohol percentage, which should be high enough to retard growth of microbial contaminants as well as to provide sensory characteristics. For example a dessert wine (high alcohol and residual sugar) typically starts with must or juice that has 30° to 40° Brix and results in 15 to 20 percent alcohol.
Demijohn  Glass jar for fermentation. It has a capacity of Just over a gallon (4.5 litres) and fills six standard wine bottles. 
Demijohn: Somewhat of an archaic winemaking term. Demijohns (or carboys) are bulbous, long-neck bottles that can hold three to 10 gallons of liquid. Traditionally they were covered with wicker weaving to protect them from breaking.
Depth Describes a wine of persistently complex and intense flavors
Diammonium phosphate/DAP  A compound that may be added to the must in order to supplement available nitrogen required to ensure yeast health. When used correctly it can help minimize stuck and/or sulfidic fermentations.
Diastase  The enzyme which converts starch to sugar and thus prevents starch haze in a finished wine. Also known as fungal amylase.  
Dissolved oxygen/DO A measure of the soluble oxygen contained within a liquid.  
Dosage In bottle-fermented sparkling wines, a small amount of wine (usually sweet) that is added back to the bottle once the yeast sediment that collects in the neck of the bottle is removed.
Dry   The opposite of sweet. A dry wine has no taste of sweetness, although it may still contain a tiny amount of sugar. 
Dry: No sugar left, i.e. from a chemical standpoint (the degrees Brix is approaching 0) and/or a sensory standpoint (the wine is no longer perceptibly sweet).
Dry Having no perceptible taste of sugar. Most wine tasters begin to perceive sugar at levels of 0.5 percent to 0.7 percent.
Earthy A wine having mushroom and/or soil characters; alternatively it can be a descriptor for characteristics Brettanomyces imparts to wines.
Egg Whites  Consisting of approximately twelve percent albumin and globulin, egg whites are a relatively gentle protein-based fining agent. Like gelatin, albumin and globulin attract suspended solids in wine including tannins. Egg whites are not suitable for fining white wines. Prior to addition, a pinch of salt and a small amount of water should be added to the egg whites which should then be whisked but not to the point of foaming. The wine should be racked off the finings within two weeks of addition.
Elegant Typically well made, balanced, lighter bodied wines
End grain The exposed end surface of the wood when cut across the grain 
Enology/Oenology The science of wines and winemaking.
Enzyme   A chemical compound which can effectively convert complex molecules (such as starch) to simpler ones (such as sugar). Enzymes produced by yeast cells convert sugar into alcohol during fermentation. 
Enzyme Protein(s) that function as catalysts in biochemical reactions. As above but also in the case of pectinase will break down pectin which makes jelleys jell.
Esters   Volatile aroma compounds formed from the reaction of alcohols and acids which are responsible for the bouquet of wine.
Ethanol/Ethyl alcohol  The principal alcohol produced by yeast during fermentation of grape must. 
Ethyl acetate A compound with the odor of nail polish remover arising from a wine with high volatile acidity
Extract  A measure of the acidity in wine. At low pH (high acid) levels, the wine has greater protection from bacterial spoilage, and are usually more intense and lively (see Total Acidity), while wines with a high pH (low acid) have a dull color. A high concentration of acidity can result in the tart taste often associated with lemons. All wine is acidic, with a pH range from about 3.1 for a crisp chardonnay to 3.8 for a soft Cabernet Sauvignon. Distilled water is neutral at 7.0, while pure lemon juice has a pH of 2.2, for example.
Extracted  A very concentrated wine 
Extraction The process of drawing out compounds into wine. 
Fat A full-bodied, thick wine.
Fermentation   The conversion of sugar into alcohol and carbon dioxide under certain conditions by yeast cells. (See also malo-lactic fermentation.)  
Fermenting Bucket AKA Primary Fermenter This is a food grade plastic bucket that is used for the primary fermination phase of wine making. They hold at least 30% more liquid than the glass vessel that will be used to perform secondary fermentation and aging. The buckets are larger to allow room for the cap and/or foam that is created during the rapid fermentation phase.
Fermentation lock or trap See air-lock. 
Fermentation Length of  The amount of time to change grape juice into wine. Depends on several factors, including: fermentation temperature (lower takes longer), the structure of the grape, and the variations in sugar content dictated by each vintage's weather conditions (the more sugar present, the longer the fermentation process). White wines are generally fermented at lower temperatures and thus tend to have a longer length of fermentation (10-15 days) than the reds (6-9 days).
Fermentation Temperature  The temperature at which fermentation took place; generally a range of about 55 to 79 degrees Fahrenheit, generally slightly higher for reds than for whites, but the goal of the winemaker is to keep the temperature as low as possible without arresting natural fermentation so as to avoid any unpleasant flavors that "hot" fermentation would impart. While the fermentation temperature is easily controlled in stainless steel tanks, it is more challenging when a wine is fermented in oak barrels, which must be isolated in a temperature-controlled room of the winery.
Fermentation Malolactic  The process of converting Malic acid (the aggressive, harsher kind like that found in green apples) into Lactic acid (the softer, creamier kind with flavors like those found in milk and butter), resulting in a softer wine. It is a natural process that is encouraged in part by low SO2 levels and a warmer temperature (above 15 degrees centigrade) at the appropriate stage than would otherwise be appropriate for storage. Reduces the acidity of a wine, biologically stabilizes it, and adds complexity to the flavor.
Filtration The removal of minute particles suspended in a wine by passing it through a filter medium. 
FILTERING  Filtration removes fragments of fruit, possible bacteria and yeast cells. This 'cleaning up' helps to improve taste, appearance and durability. Filtration enhances the quality of the wine. Filtration is commonly done by pressing the wine through filter pads which retain the solids. Filter systems are available in many different types.
Fining  The clearing of a wine by adding any substance which will coagulate suspended matter and form a sediment.
FINING Clearing the wine by chemical or non mechanical means. Certain types of cloudiness or haze may appear in wine. Each type has a type of additive that work to clear the haze. Types of common fining agents include Bentonite, and Sparkolloid. Egg whites have also been used in fining wine. See Finning Chart for additional information. 
Fining/Collage Method of  The technique used to clarify wine and remove excess levels of certain natural elements in wine to achieve balance of the remaining components, resulting above all in improved clarity, perfume and stability. It is a process of hydrogen bonding wherein the fining agent (egg white, bentonite clay, gelatin, etc.) is passed through the wine, absorbing a specific amount of the undesired element, and then removed to result in brilliant, or less cloudy, wine.
Fining: A winemaking technique involving the addition of a material such as egg whites, bentonite, milk, casein, gelatine, etc. for clarifying wines.  This operation is done before bottling to help ensure the product will not be cloudy or flocculant in the bottle.
Finish The key to judging a wine's quality is finish, also called aftertaste--a measure of the taste or flavors that linger in the mouth after the wine is tasted. Great wines have rich, long, complex finishes.
Finished wine  Wine in which the processes of fermentation and clearing are complete. 
Flabby/Flat Wines low in acidity 
Fleshy A wine with a soft, smooth texture.
Flinty A stone or mineral-like character.
Floral Tasting and/or smelling of flowers
Flor  A growth of yeast cells formed on the surface of a wine during the making of sherry. 
Fortification  The addition of alcohol to a finished wine to increase its alcoholic strength. 
Fragrant A fragrant wine is very aromatic and flowery. Common wine fragrances are floral, spice, and fruit aromas such as pineapple, blackberry, peach, apricot, and apple. The variety of the grape is primarily responsible for a wine's fruit fragrances.
Free-run Wine or juice that is obtained without pressing 
Free SO2/FSO2 The unbound portion of SO2 forms available for antimicrobial activity
French oak Oak of the genus/species Quercus robur, or Quercus petraea harvested in France
Fructose  A simple sugar, one of the constituents of sucrose.  
Fruit bomb Soft wines from very ripe grapes that contain big fruit flavors and low acid levels 
Fruity A fruity wine is one in which fruit flavors dominate the aroma and taste. Often these wines are easy-drinking and light.
GELATIN  Finning agent to reduce tannins and astringency. Can over strip. Use 1 package or less dissolved in water. 
Glucose  Another simple sugar; the other constituent of sucrose (see fructose). 
GLYCERIN If the wine is 'thin' a couple oz. of glycerin gives the impression of a wine with more body. Glycerin will also add some sweetness to wines. It can be used with sugar syrup to sweeten wine.
Glycerin: Also known as glycerol, glycerin is a carbohydrate (sugar) that is not a substantial food source for most wine yeast strains, though it can be consumed by some lactic acid and acetic acid bacteria. It is sometimes added to wine to increase a wine's body and, in higher amounts, sweetness.
Grams per Milliliter  A unit of measure for the amount of acid (grams) in a quantity of wine, juice or must (milliliters) that is typically abbreviated g/ml. Grams per milliliters corresponds directly to tenths of a percent such that as an example, 7 g/ml is equal to 7 tenths of a percent or 0.007. For iWinemaker calculators, enter acid levels an integer plus up to one decimal place, for example 7.5. 
Grape sugar  Glucose and fructose. 
Grape Tannin Found in skins and stems of grapes, tannin adds astringency or zest to wine. Also aids in the clearing process. Tannin occurs naturally in red wines which are fermented in the skins, but must be added to white wines.
Gum Stopper The gum stopper (also known as a bung) works in concert with the airlock to ensure an airtight seal at the neck of your carboy during fermentation. A hole is drilled down the center to allow the attachment of the airlock. Order one for each carboy you own, plus a couple extra, since they have a tendency to disappear when you need them the most!
Hard Use: Usage varies according to the grape or fruit, but generally, you would add no more than 1/4 teaspoon per gallon to fruit wines. Not needed if making wine from a kit.
Hazy  Used to describe a wine that has small amounts of visible matter. A good quality if a wine is unfined and unfiltered.
Herbaceous Describes a wine that smells or tastes grassy or green. Often a characteristic of wines made from Sauvignon Blanc and Sémillon grapes. Can also be found in very young wines that will change flavor as they age. Primarily a function of the grape variety, not soil or climate.
Hogshead Usually a 60-gallon oak barrel
Hot Unbalanced high alcohol wines.
Hungarian oak/"European" oak Oak of the genus/species Quercus robur, or Quercus petraea harvested in Hungary
HYDROGEN SULFITE A gas produced by yeast causing the 'rotten egg' smell. More often produced at warmer fermentation temperatures. Often removed by racking the wine. If severe, can be removed by copper sulfite as a last resort.  
Hydrometer  An instrument for estimating the sugar content of a must or finished wine. 
HYDROMETER A glass bulb device used to measure the specific gravity (S.G.) of juice or wine. The sweeter the liquid, the higher the hydrometer will float and the higher the specific gravity. The wine making hydrometer has three scales, specific gravity, brix and potential alcohol. The suggested starting point for brix is about 21, specific gravity is about 1.085. This will give you a wine of about 12% alcohol. The desired finished wine will be your guide for the actual starting level. 
Hydrometer: An inexpensive and widely available analytical device that measures the specific gravity (relative density) of a solution. Very useful to measure the amount of sugar (in Balling or degrees Brix) in a juice or wine. Because density depends on temperature, a thermometer reading of the solution being tested is critical for accurate results. Hydrometers are calibrated to be used at 60° F.  
Inoculate  To add an active culture of yeast or malolactic bacteria to a must, juice or unfinished wine. 
Invert sugar  A preparation of glucose and fructose obtained by boiling sucrose solution with some added citric acid. Yeast can ferment invert sugar, but has to convert sucrose enzymatically to glucose and fructose before fermentation.
Invert sugar Common sugar (sucrose) that has been broken down into fructose and glucose. It does not contain dextrins. One pound of invert sugar is only two-thirds as sweet as cane sugar, so you have to use 50 percent more to achieve the same sweetness.
Invertase The enzymes produced by yeast which convert sucrose into glucose and fructose.
Isinglass  A proteinaceous compound used to fine wine. A semi transparent whitish very pure gelatin prepared from the air bladders of fishes (as sturgeons) and used especially as a clarifying agent and in wine, jellies and glue.
ISINGLASS Gentle fining agent. Settles yeast in white wines. Doesn't work in reds. Use 4 oz. liquid to 5 gallon.
Lactic acid  An acid produced during the malo-lactic fermentation. Can also be added to a wine must in place of citric, malic or tartaric acid; it helps develop a good bouquet. 
Lactic acid An acid present in wines that have undergone a malolactic fermentation, in which the malic acid (see below) has been transformed into lactic acid by malolactic bacteria. Lactic acid is less acidic than malic acid.
Lean A wine is lacking in density and structure
Lees See sediment.  Gentle fining agent. Settles yeast in white wines. Doesn't work in reds. Use 4 oz. liquid to 5 gallon.
Lees: The spent yeast cells that accumulate on the bottom of winemaking vessels after the population has completed the fermentation and has died out. Wine is usually racked (siphoned) off the lees to make it more presentable and to exclude any undesirable sensory effects that extended lees contact might impart.
Legs  The viscous droplets that form and ease down the sides of the glass when the wine is swirled. A gauge of body in the wine.  The more pronounced the legs the higher the body.
Length The amount of time the sensations of taste and aroma persist after swallowing. The longer the better.
Limousin A type of French oak cask, from the forests of Limoges, France
Light  A term used to describe the body or color of a wine. A light wine is usually easy to drink and not high in alcohol. Muscadet is a light white wine. Beaujolais is an example of a light red wine.
Litmus paper A small strip of treated paper used in wine making for checking the acid level of a juice.  True litmus paper only comes in two types red litmud for testing for ph above 7.00 and blue for testing for acid.  PH meters are greatly prefered.
Lysozyme This solution is used in wine to hinder or prevent a malolactic fermentation. It controls lactic acid bacteria and is made from an enzyme which naturally occurs in egg whites. A web page from Scott Lab explains what lysozyme is, how it works, and recommended dosage. Use: Add 1 oz per 5 gallons of wine, which provides about 250 ppm.
Mature Ready to drink.
Maceration Maceration is the winemaking process where the phenolic materials of the grape— tannins, coloring agents (anthocyanins) and flavor compounds— are leached from the grape skins, seeds and stems into the must. The term is usually used in reference to wine, but is sometimes used with other drinks, such as piołunówka, Campari and crème de cassis. It is also the term used to describe the process of steeping unflavored spirit with herbs for making herb-based alcohol like Absinthe. Maceration is the main process by which the red wine receives its red color, since 99% of all grape juice (with the exceptions of teinturiers) is clear-grayish in color. In the production of white wines, maceration is either actively avoided or allowed in very limited manner in the form of a short amount of skin contact between the must prior to pressing. This is more common in the production of varietals with less natural flavor and body structure like Sauvignon blanc and Sémillon. For Rosé, red wines grapes are allowed some maceration between the skins and must, but not to the extent of red wine production. 
Maceration Maceration is the process of steeping the skins and solids of the grape in the must, the aim being to extract the tannins, flavour compounds and colouring agents. Maceration varies according to the phenolic content of the grape variety and the style of wine targeted by the wine making. Although maceration naturally occurs during the fermentation of red wine, many wine makers encourage an additional maceration period after fermantation has finished. Cold maceration is a pre-fermentation process and it therefore involes the aqueous extraction rather than the alcoholic extraction of the phenolic content. The aim of this practice being to produce greater fruit and aromatic qualities as well as adding colour and complexity to the wine.
Maceration The processes through which red wine grape (or other fruit) skins, seeds, and pulp are mixed and mashed in with the fermenting juice to extract tannins, colored compounds, and aroma from the grapes. Different maceration programs have different effects. For example if you stir red wine while it ferments (often called "punching down") twice a day as opposed to once a week, you should extract more color and tannin from the skins and seeds of the grapes into the finished wine than if your strategy was less aggressive.
 Maceration, Extended Letting the red grapes sit for a while before being pressed, so that the flavor and richness develops. 
Macro-aeration Dosing large amounts of air into the must or wine. This process is common during primary fermentation.
Macro-oxygenation Dosing large amounts of pure oxygen into the must during fermentation.
Maderized A wine that has developed oxidized characters
MALIC ACID Found naturally in apple wine. Generally not used as an additive to most wines unless in acid blend. It is most susceptible to problems like malo-lactic fermentation. 
Malic acid: A naturally occurring grape acid that decreases with ripening. It is one of the principal components of a wine's total acidity. If a wine is too acidic (the grapes hadn't ripened fully), it can be de-acidified by a malolactic fermentation, in which the malic acid will get metabolized by malolactic bacteria and excreted as lactic acid.
Malo-lactic fermentation  A reaction caused by the lactic acid bacterium converting malic acid into lactic acid in a wine where the normal fermentation is complete. Can be avoided by careful hygiene and sterilization. 
Malo-lactic Fermentation: Very different than alcoholic fermentation, malo-lactic fermentation occurs when a strain of lactic acid bacteria is introduced by chance or on purpose into a finished grape wine. These bacteria convert the malic acid (a natural grape acid) in the wine into lactic acid, a less potent acid, as well as contributing some flavor and aroma to the wine. Usually described as "buttery" or "caramel," this malo-lactic aromatic profile is especially desirable in quality red wine production as well as some whites, such as Chardonnay.
Matrix The sum of all components making up a wine
Maturation  The change in wine which takes place during storage. It involves subtle chemical changes that produce a good bouquet and the precipitation of excess tannin (in red wines) to form a sediment. The flavor of a wine mellows during its maturation. 
Mature Wine which has reached its optimum point during aging. It is neither too young nor too old. It will exhibit a pleasing combination of sensory properties, aroma, flavor, texture.
Mead Wine made from honey.   
Mead  A wine, common in medieval Europe, made by fermenting honey and water. Recently mead has enjoyed new popularity. Wine makers now make flavored mead.
Mercaptans Unpleasant sulfury rotten smells found in some defective wines.
Meso-climate The unique climate of a small subsection of a wine region
Metabisulphite  Sodium or potassium metabisulphite powder. It dissolves in water to form a potent sterilizing agent, sulphur dioxide gas. Potassium metabisulfite is prefered.
Methanol  Methanol is wood alcohol, and is poisonous. It is made normally from wood, coal or natural gas. This is NOT the kind of alcohol created in winemaking.
Méthode Champenoise  French term for the method used to make champagne, which is fermented in the bottle. French champagnes and many other sparkling wines are produced using this traditional French technique. The monk Dom Pérignon is credited with inventing this method.
Micro-oxygenation/Micro-ox/MOX  Dosing minute amounts of pure oxygen into the wine during aging
Milligrams per Liter  A unit of measure for the amount of free sulfites (milligrams) in a quantity of wine, juice or must (liters) that is typically abbreviated mg/L. Milligrams per liter corresponds directly to parts per million (ppm) such that as an example 50 mg/L is equal to 50 ppm. 
Monomer A simple molecule that can be linked in a repeated fashion to form oligomers and/or polymers 
Mulled Wine  Red wine that has been mixed with sugar, lemon, and spices, usually including cinnamon, cloves, and nutmeg. Served hot.
Must Must (from the Latin vinum mustum, “young wine”) is freshly pressed fruit juice (usually grape juice) that contains the skins, seeds, and stems of the fruit. The solid portion of the must is called pomace; it typically makes up 7%–23% of the total weight of the must. Making must is the first step in wine-making. Must is also used as a sweetener in a variety of cuisines.
Must A red-wine making term that refers to the soupy mass of squished skins, seeds, and pulp that are fermented together. "Must" can also be applied to fruit winemaking; it refers to the gloppy pulp/skin mixture to which the yeast are added, essentially the winemaker's raw material. In contrast if the pulp and other solids are pressed off before fermentation, the raw material is simply "juice."
Nevers Forests surrounding the town of Nevers where French oak is harvested.
Nutrients  Chemical compounds (ammonium sulphate, phosphate and vitamin B) which encourage the growth of yeast.
Nose The smell of a wine, combining both its aroma and bouquet
Oak The most popular wood for constructing barrels. Oak imparts flavors and tannin to wines during the barrel aging process; home winemakers can also accomplish this by using oak chips or powder.
OAK (CHIPS OR SHAVINGS) Oak chips or shavings adds an oak flavor to wines. Used instead of oak barrels. Use about 3 oz of chips per 5 gallons of wine. Put chips in nylon bag with a weight to hold the chips into wine. Chips produce greatest oak flavor in 1st week, but can be left in longer for additional oak flavor and tannin. 
Oaky A wine that has extensive aromas and flavors derived from toasted oak. 
Oligomer A medium sized compound made up of a linked series of repeated simple monomers. When dealing with wine phenolics this term is used for compounds with an average of 2-5 subunits 
Organoleptic The aroma and taste properties of a material
Oxidation  A process whereby alcohol is converted to aldehyde compounds, thus spoiling a wine's flavor, colour and bouquet. However, carefully controlled oxidation can be used to produce sherry.
Oxidation: Chemical term relating to the reaction of juice, must, or wine with oxygen. Typical negative side effects of such reactions are browning of wine and juice and "cooked" flavors and aromas. Limited amounts of oxidation are actually healthy for wine, because yeast need oxygen to grow during the initial stages of fermentation. Protracted, slow oxidation is a key physiological change that takes place when a wine ages.
Oxidized Describes wine that has been exposed too long to air and taken on a brownish color, losing its freshness and perhaps beginning to smell and taste like Sherry or old apples. Oxidized wines are also called maderized or sherrified.
OXYGEN (OXIDIZE) Oxygen is a gas that readily combines with wine and chemicals, in most cases causing a bad reaction. When combined with wine, the wine oxidizes, may take on a brown color, and will deteriorate the wine. There are several ways to reduce wine from oxidizing, use of ascorbic acid, carbon dioxide for topping off the carboy, using SO2, metabisulfite or campden tablets will help reduce wine from oxidizing. There are other ways too complex for this general information. When oxygen mixes with chemicals, it generally reduces the strength of the chemicals, causing them to be less effective. Try to keep oxygen away from chemicals by keeping the cap tight.
Peak The time when a wine tastes its best--very subjective.
Pectic enzyme   An enzyme needed to break down pectin, a gummy carbohydrate substance found in fruit which may cause haziness in a finished wine.  
PECTIC ENZYME Use when starting wines. Helps break down pulp and clears pectic haze. Helps extract color from grapes and fruit. This has been a powder in the past but is now coming in a liquid form. If you have the powder, use 2-1/2 tsp. per 5 gallons. The liquid may differ in drops per gallon, so read instructions. Use the recommended amount when making recipes. 
Pectins: Complex carbohydrate chains naturally occurring in fruits that can contribute to the viscosity and haziness of a wine. They are the active ingredeant of surejell. They can be shortened and solubilized (dissolved) by pectic enzymes, which are sometimes used in winemaking when dealing with non-grape fruit.
(pH) A scale from 0 to 14 used for expressing the acid level of a substance. The higher the number the lower the acid. The range for fruit is a pH between 2 and 4. 
(pH) A measure of the acidity in wine. At low pH (high acid) levels, the wine has greater protection from bacterial spoilage, and are usually more intense and lively (see Total Acidity), while wines with a high pH (low acid) have a dull color. A high concentration of acidity can result in the tart taste often associated with lemons. All wine is acidic, with a pH range from about 3.1 for a crisp chardonnay to 3.8 for a soft Cabernet Sauvignon. Distilled water is neutral at 7.0, while pure lemon juice has a pH of 2.2, for example.
(pH) papers A small strip of treated paper used in wine making for checking the acid level of a juice. Has a limited sensativity and red wine interferes with color change.  It is recommended thst pH meters be used for a more accurate and reliable test.
Pigeage When you make a red-grape wine, the skins of the red grapes form a 'cap' on top of the wine while it ferments. This cap must be broken up and stirred back into the wine to give it a lot of contact. This breakingup is called pigeage. 
POLYCLAR Fining agent. Reduces tannins. Helps reduce some browning. Use 1-3 gr./gal 1 tsp.=.9gr 1/4 oz liquid to 5 gallons 
Pommace The remainder pulp and skins after pressing 
Polymer A large compound made up of a linked series of repeated simple monomers. When dealing with wine phenolics this term is used for compounds greater than an average of 5 subunits long 
POTASSIUM BICARBONATE Used to reduce acid in wines or must. Works well with cold stabilizing. 1 tsp=6.1gr.
POTASSIUM BITARTRATE (CREAM OF TARTER)  Promotes better cold stabilization at higher temperatures. Use 3.4 gr./gal or 1 tsp per gal. and stir hard for 0.1% acid reduction
Potassium Metabisulfite Potassium metabisulfite is added to wine to inhibit bacteria and yeast growth, as well as slow down oxidation. It may leave an unpleasant aftertaste in wine if the dose is too high. This chemical is also used in a water solution as an antiseptic rinse to sanitize equipment. It is similarto, but better than, Sodium Metabisulfite, because it does not add sodium to one's diet. CAUTION: Some people, particularly asthmatics, can have a severe allergic reaction to this substance. Use: For wine: 1/8 teaspoon (1 gram) of powder per gallon of wine provides 150 ppm free SO2. A little bit goes a long way, so be careful! Always test the free S02 content of your wine (using Titrets and Titret holder) to determine the proper amount to add. Generally speaking, the target free SO2 for red wines is 20-30 ppm and 25-40 ppm for white wines. The exact target depends upon the pH of the wine. For sanitizing solution: Dissolve 1 to 2 oz. (2 to 4 tablespoons) Potassium Metabisulfite powder in one gallon of water.
POTASSIUM METABISULFITE 57% SULFUR DIOXIDE (SO2) Use at start of must, at each racking and at bottling. Do not add while under fermentation. Prevents molds and bacteria. Helps prevent oxidation. Used to clean and sterilize wine bottles. It has a limited shelf life. Add 1/4 tsp. to 5 gallons wine for 50-75ppm mixture.  
POTASSIUM SORBATE Sold as white elongated pellets, this chemical prevents yeast reproduction, thus preventing renewed fermentation. I have seen it listed as an ingredient on many grocery items in your refrigerator from apple juice to taco sauce. It is used by the winemaker when sweetening a wine after it has stopped working, or to stop a fermentation before a wine becomes too dry.
Potassium Sorbate  USE Use: Add 1/4 teaspoon per gallon of wine. grapestompers recommends using one crushed Campden tablet per gallon of wine in concert with potassium sorbate, because sorbate tends to work better in the presence of sulfites. Be sure to stir well, and let the dead yeast cells settle before final racking prior to bottling. 
Press The act of using pressure to force juice out of fruit pulp. Also the device used to carry out this operation. 
Primary Fermentation: The first vigorous "rolling" fermentation, in which yeast convert sugar in the wine to alcohol and carbon dioxide. At this stage it is all right for the fermentation vat to be exposed to the air because the yeast are producing so much carbon dioxide that it forms a "blanket" of this inert gas over the fermenting juice or must. Once the yeast start to die down and the fermentation is less active, it's advisable to move your wine into a carboy or barrel to exclude air and possible contaminants (see Secondary Fermenation).
Primary fermentation   See aerobic fermentation.  
Procyanidins Skin and seed tannins derived from catechin,  epicatechin, gallocatechin or epigallocatechin monomers 
Pulp fermentation   Any fermentation conducted in the presence of the pulped fruit or other ingredients.  See also Primary fermentatio.
Pumpover The process of dousing the cap at the top of a tank with wine from the bottom of the tank
Rack and return/Delastage Removing all of the wine from one fermenting tank to another tank leaving the cap behind. After a set period of time the wine is pumped back over the top of the cap.
Racking  A process of siphoning a wine off the sediment formed during fermentation.  
RACKING  The process of removing wine from the sediment. This is generally done by siphoning the wine, leaving the sediment behind. The first racking should be when the specific gravity is about 1.010-1.005. Rack from the primary fermentor into the secondary fermentor. After that, racking should be done after the wine has cleared 3 weeks or 1-2 weeks after adding Sparkolloid. As a rule, add 1/4 tsp. metabisulfite to the wine at each racking.  
Reduced/Reductive Generally refers to negative sulfur containing aromas such as sulfides or mercaptans
Rehydration A vital step in the preparation of yeast where 80 to104 0F water is added back to freeze dried yeast cultures. Reviving the yeast and preparing them for growth.
Remontage The process of pumping the liquid over the macerating cap of solids during fermentation that serves to encourage the alcohol to extract the colour and tannin from the skins.
Reverse Osmosis: An expensive and inconvenient commercial process through which alcohol and acetic acid can be removed from the wine so that it meets aesthetic or, more commonly, regulatory levels.
Robust A full-bodied and intense wine.
Round A smooth balanced wine.
Ropiness: A condition in which wine resembles slime, raw egg whites, or mucous. It is caused by an extreme microbiological contamination that produces long-chain carbohydrates (polysaccharides), hence the "ropiness."
Saignee Bleeding off a portion of juice after only a short period of skin contact to increase the skin to juice ratio of the remaining must thus concentrating the wine.
Seasoning The process of aging wood in the natural elements to soften tannins, reduce astringency, and increase complexity 
Secondary fermentation See anaerobic fermentation.   A yeast inhibitor which keeps wine from re-fermenting after sugar is added at bottling. Keep from light. Shelf life about 1 year. To be used with potassium metabisulfite. Use 2-1/2 tsp. to 5 gallon.  
Secondary Fermentation: A bit of a misnomer, secondary fermentation can refer to two things: 1) A true second fermentation that follows completion of the first. Usually purposely started by adding yeast and extra sugar to the finished wine to make CO2 for a sparkling wine effect. 2) The second stage of the primary fermentation. After vigorous primary, wine is transferred to a carboy or barrel (secondary fermenter) to finish the last, protracted "secondary fermentation" when the yeast are slowing down and the wine needs to be protected from oxygen and any air-borne microbial contaminants.
Secondary Fermentation Synonymous with malolactic fermentation in still winemaking. In sparkling winemaking it is the process of fermenting in bottle to produce the carbon dioxide bubbles.
Sediment   The deposit formed at the bottom of the fermentation vessel when fermentation is complete. It is composed of dead or dormant yeast cells, fruit sediment, and so on.  
Settling The natural precipitation of solids in wine.
SO2/Sulfur dioxide A compound used to prevent wine spoilage (see potassium metabisulfite) 
SO2 Free  The amount of sulfur dioxide that has not chemically bound to other components, making it inactive. In other words, the most detectable amount of sulfur in the wine, which should be a significantly lower number than the total.
SO2 Total  A measure of total (free and bound) sulfur dioxide in wine. SO2 is a natural by-product of fermentation that in appropriate amounts is a natural component in healthy wines. The level of SO2 can be controlled by using yeasts that produce little or none. In judicious proportion it improves the color and primary aromas of a wine, acting as an anti-bacterial, anti-browning and anti-oxidation agent. In excess it can cause off flavors and negative reactions to those who are extremely sensitive to it. At Castello Banfi, steps are taken - mostly through hygienic conditions, low-oxygen fermentation environments and careful grape selection -- to maintain the lowest possible levels of sulfur dioxide in our wines.
Sodium Benzoate This is another chemical used to stabilize wines (slow down yeast growth and inhibit fermentation); generally preferred by makers of fruit (non-grape) wines.
Soft Use: Add one crushed tablet per gallon of wine and stir well; works best in the presence of sulfites, so you should also add one crushed Campden tablet for every sodium benzoate tablet. Allow yeast to settle as lees before final racking and bottling. Each tablet contains 250 mg of Sodium Benzoate.
Sparge To introduce gas into a liquid
SPARKOLLOID Good general fining agent. Hot mix. Mix with water and boil about 30-45 minutes. Add water as needed. Mix with wine while hot. Wine should clear in about 1-2 weeks. May not be desired in some red wines. Use 1 tsp per gallon. 
Sparkalloid Sparkalloid is used as a fining agent. Use: 1/2 teaspoon per gallon of wine. Mix required amount of powder with a small amount of cold water. Mix well until solution is smooth and creamy. Add mixture to finished wine and stir. Let wine settle for a week or more, then rack.
SPECIFIC GRAVITY Ratio of mass of liquid to mass of distilled water. Scale on hydrometer used to measure the sugar content or sweetness of the juice or wine. 
Stave  A narrow strip of wood used to make barrels.
Still wine Any wine that is not sparkling.
Straining Bags  Adding flavors to wine is great.... until you have to fetch the oak chips, berries, etc. from the wine. By using these straining bags, you can eliminate the frustration and time spent gathering up the remnants of your added ingredients. They are used much like a tea bag.
Straining Bags  A good source for straining bags sre paint straining bags from your local big box lumber store they are much cheaper the HBS products.
Stuck fermentation  A fermentation that has started but then stops before desired levels of sugar were converted into alcohol.
Structure A combination of the texture, mouthfeel and balance that a wine imparts. 
Sucrose   The chemical name for ordinary household sugar. It is composed of glucose and fructose molecules combined to form a complex sugar.  
SUGAR  If juice has a low brix, it should be brought up before starting fermentation. This can be done by adding sugar. Add 1.5 oz sugar per gallon to increase brix 1 degree. Add 7.5 oz or about 1/2 lb sugar for 1 degree brix increase in 5 gallons. 5 lbs sugar will increase brix about 10.7 degrees. These figures are approximate. Measure with a hydrometer.
Sugar, Residual  The sweetness of a wine is defined by the level of residual sugar (or RS) in the fermentation process. Residual sugar is the measure of the amount of sugars that remain unfermented in the finished wine.
Sugar, Residual  Residual sugar is usually measured in grams of sugar per litre of wine. Even among the driest wines, it is rare to find wines with a level of less than 1 g/L, due to the unfermentability of certain types of sugars, such as pentose. By contrast, any wine with over 45 g/L would be considered sweet, though many of the great sweet wines have levels much higher than this.
Sugar, Residual  Any sugar left in the wine after the fermentation is complete and the yeast have completed their life cycles and have died out. Sometimes residual sugar is desired, as in sweeter white wines or dessert wines. Residual sugar that is perceptible on the palate is seen as a defect in most red table wines.
SUGAR SYRUP Used to sweeten before bottling. 2 parts sugar to 1 part water. Heat mixture to make a syrup consistency and let cool completly before adding. Be sure to add POTASSIUM SORBATE to sweetened wine. 
Sulfides Sulfur containing compounds that can impart negative rotten aromas to wine 
Sulfites A class of sulfur-containing compounds used in winemaking as an antimicrobial agent, as an antioxidant, and as a preservative. A respiratory hazard in its undiluted state, sulfites need to be handled carefully but are entirely safe at the levels in which they are used for winemaking. If you are asthmatic and lack the enzyme sulfite oxidase, you should not consume foods or beverages that contain sulfites.
Sulfites Sulfites are sulfur containing compounds that are natural by-product of fermentation. Sulfites are also used as a wine preservative (see potassium metabisulfite) 
sulfidic fermentations Fermentations resulting in off oders of hydrogen sulfide or “rotten eggs”
Sulphur dioxide  (SO2) The gas produced by dissolving sodium metabisulphite powder in water. It acts as a sterilizing agent.  
Sulfur dioxide In the form of potassium metabisulfite crystals, liquid sulfur dioxide, or sulfur dioxide gas, sulfur dioxide is an effective and safe preservative, antioxidant, and antimicrobial agent that has been used for millennia to facilitate the winemaking process. It is a respiratory irritant in high concentrations, so it should always be handled with care. Usual levels of free sulfur dioxide in table wines is about 20 to 40 parts per million.
Supple Big velvety textured wines
Sur lie The French term for leaving the wine in contact with its lees and "bâtonnage" the term for stirring this lees back up into the wine. 
Sur lie The French term for leaving the wine in contact with its lees and "bâtonnage" the term for stirring this lees back up into the wine. 
Sweet wine: Any wine in which there is perceptible residual sugar. Sugar is perceptible, depending on the individual taster and the composition of the individual wine, at about 1.5 percent.
TANNIC ACID (GRAPE TANNIN) Tannin is found naturally in grapes and is made from powdered grape skins. Tannin is needed in apple, and some whites. Use 1/4-1/2 tsp. per 5 gallon.
Tannin  An astringent substance which is an important ingredient of many wines, providing a vital element of the overall flavor. 
Tannin: The astringent phenolic anthocyanins found in grape skins, seeds, and stems that make your mouth pucker and feel dry when you drink red wine. Tannins are extracted from the grapes during the maceration process.
Tannins Tannins (mainly condensed tannins) are found in wine, particularly red wine. Tannins in wine can come from many sources and the tactile properties differ depending on the source. Tannins in grape skins and seeds (the latter being especially harsh) tend to be more noticeable in red wines, which are macerated (soaked with skins and seeds) and sometimes fermented while in contact with the skins and seeds to extract the colour from the skins. The stems of the grape bunches also contain tannins, and will contribute tannins if the bunches are not de-stemmed before pressing, maceration, and/or fermentation
TARTARIC ACID This is most the predominate acid in grapes. It is the most stable acid, adding for flavor, color and stability. Use when making fruit wines. 1 tsp = 4.8 gr. 
Tartrates Crystals of Potassium tartrate that have precipitated out of the wine solution after having been formed by reacting tartaric acid with Potassium from potassium containing salts.  AKA cream of tartar crystals.
TCA: 2,4,6-Trichloroanisole, a chemical compound that is one of the major sources of the "cork taint" off-odor.
Terroir There is no exact translation into English for this much used and sometimes controversial term. In general terroir applies to the natural environment of a viticultural site including, soil, topography and microclimate. 
Thief A tubular glass, plastic or wooden instrument for drawing a sample of wine from the cask or barrel. 
Thin A wine lacking body.
Titration A chemical analytical method used to determine total (or titratable) acidity. A strong base (such as sodium hydroxide), the opposite of acid, is added to a must, juice, or wine in measured amounts. If an indicator chemical (such as phenolphthalein) has been added to a sample of the liquid being tested, then a color change will occur at the point when all of the available hydrogen ions in the acids have been neutralized by the base. The total (or titratable) acidity of the must, juice, or wine can then be determined in relation to how much base it took to neutralize all of the acids in the wine.
Toasting The process of heat treating oak. Charing the inside of barrels
Toasty A flavor imparted by fire treated oak
Total SO2/TSO2 The entire amount of SO2 in all of it forms contained within the wine 
TOPPING OFF Reducing open space in the carboy by adding wine, water, CO2, or even marbles will reduce space where oxygen could get to the wine. Topping off with water will dilute wine. Before topping off any wine, seek advice from winemaker or your local brew shop.  
Trub See Lees, above. 
Turbidity The decrease in transparency of a solution due to suspended solids
Ullage  The air space between the surface of the wine and the bottom of the bung, cork or other closure. 
Varietal character The aromas and taste sensations typical of a particular grape variety.
Vegetal A description of wines that have green vegetables odors
Velvety A soft, silky, lush mouthfeel
Venturi A valve that draws air into a fast flowing liquid
Viniculture The science or study of grape production for wine and the making of wine.
Vinegar  Acetic acid. This may be formed in a wine if it becomes infected by types of bacteria often carried by the "vinegar fly" or fruit fly  Drosophila. 
Vinification The practical art of transforming grapes into wine.
Vinometer  This instrument measures a wine's alcoholic content. 
Vinous A wine without a specific, distinguishing odor.
Viticulture: The science of grape growing.
Vitis vinifera The species of grapevines most responsible for producing the world's best wines, including Pinot Noir, Chardonnay, Cabernets, etc.
Volatile Acidity: Acid created during fermentation by spoilage organisms that are introduced by contact with fruitflies or other air-borne insects and contaminants. Refers usually to acetic acid (vinegar) produced by contamination by acetobacter bacteria. Keep fermenting wine covered to avoid problems.
Volatile acidity/VA A measure of the low boiling point acids in wine. High levels of volatile acids, notably acetic acid, are an indicator for wine spoilage 
Whole cluster press The process of pressing intact clusters of grapes without destemming or crushing the fruit first
Wine The fermented juice of grapes
Yeast A small, single-celled organism, Saccharomyces, which carries out fermentation. Only the true wine yeast can work adequately for the home-winemaker. 
YEAST Wine yeast is specially developed for making wine. Several types of wine yeasts are available, each produce a desired effect in the wine. Wine yeast is more tolerant of SO2 then is wild yeast.  
YEAST Yeast is a fungus. There are literally thousands of different types of yeasts. The type most useful to people are the related species and strains of Saccharomyces cervisiae. Wine yeasts are in this group. When choosing a yeast buy a Champagne-type dry wine yeast. Both Lalvin and Red Star have consistent quality, low-foaming yeasts. I would recommend either of these brands. Do not use bread yeast it is designed to generate lots of CO2 for rising of bread.
Yeast -Bread Bread yeast provide lots of CO2 for raising bread. Good wine yeasts are sulphur tolerant. Sulphur tolerance enables a yeast to survive, reproduce and feed in a must in which harmful bacteria find it impossible to survive. 
YEAST ENERGIZER Sold as a fine white powder, you may use it to restart stuck fermentations. It is a blend of amino acids and vitamin compounds.
Yeast Food (or Yeast Nutrient): A pre-calculated commercial mix of vitamins, minerals, and amino acids added to juice or must to ensure a clean, complete fermentation. Adding it to non-grape wines is essential because many fruits lack high enough nitrogen levels to support healthy yeast growth.
Yeast Hulls  The remnants of expired yeasts, yeast hulls or yeast ghosts provide live yeasts with nutrients that promote a more complete and trouble-free fermentation. Yeast hulls are an ingredient in most commercial yeast nutrient preparations. 
yeast:   Wild  Sometimes referred to as "natural yeast," wild yeast are the yeast fungi that are present naturally on grapes, on winery equipment, and just in the air itself. Many wineries rely on these itinerant microorganisms to start their wine fermenting, but since these yeast strains are far from uniform in population and "good" fermenting ability, using "natural fermentation" (and not inoculating with a proven pure culture) can be a serious risk. Wild yeast have been known to cause stuck fermentations, high hydrogen sulfide concentrations, and visual defects in finished wine, as well as a host of other spoilage reactions.
Zymase  The enzymes produced by yeast which convert glucose and fructose into alcohol.
zymology  AKA zymurgy the branch of chemistry concerned with fermentation (as in making wine or brewing or distilling
Wine Glossary  Stavin 
Fine Vine Wines
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