Glossary of Wine Making Terms

This glossary has many of the terms most commonly encountered in wine making. Expand your vocabulary and use the same wine making brewing terminology as professional wine makers.

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A-A-A

Acetic Acid
Acetic acid, also called “ethanoic acid”, is a commonly used chemical reagent and food additive. In food products acetic acid is produced by the fermentation of sugars by yeast. It gives vinegar as well as kombucha their signature tang. Vinegar is legally defined as having 4-8% acetic acid. kombucha typically has less than 1% acetic acid.
Acidity
The quality of wine that gives it its crispiness and vitality.  The three main acids found in wine are tartaric acid, malic acid and lactic acid. A proper balance of acidity must be struck with the other elements of a wine or the wine may be said to be “too sharp” for having too high levels of acidity or “too flat” for having too low levels of acidity.
Aerobic
Winemaking in conditions that promote exposure of the wine to oxygen, such wine barrels only partially filled to leave room for air to oxidatively age the wine.
Aging Barrel
A barrel, often made of oak, used to age wine or distilled spirits.
Alcohol
Ethyl alcohol. The colorless primary alcohol constituent of beer, wine and other distilled spirits.
Alcohol by Volume
ABV. A worldwde standard measure of the volume of ethyl alcohol (ethanol) contained in a given volume of an alcoholic beverage expressed as percent of total volume. Chemically, ABV is defined as the number of millilitres of pure ethanol present in 100 ml of solution at 20°C. The number of millilitres of pure ethanol is the mass of the ethanol divided by its density at 20°C, which is 0.79 g/ml. In English units this is the number of fl oz. of pure ethanol present in 3.5 fl oz of solution at 68°F. The number of fl. oz. of pure ethanol is the mass of the ethanol divided by its density at 68°F, which is 0.46 oz/cu in.  Abbreviated as “ABV”, “abv”, or “alc/vol”. 
Alcohol by Weight
ABW. A measurement of the percentage weight of ethyl alcohol per volume of wine. For example,  10 percent alcohol by weight equals 10 fl. oz. of alcohol per 100 fl.oz. of wine . This measure is always lower than Alcohol by Volume. To calculate the approximate Alcohol by Weight, divide Alcohol by Volume by 1.25. Similarly, to calculate the approximate Alcohol by Volume, multiply Alcohol by Weight by 1.25. Abbreviated as “ABW”, “abw”, or “alc/wt”. 
Amino acids
Proteins found in wine grapes that are formed by fruit esters and consumed during fermentation. They contribute to the sense of complexity in a wine.
Anaerobic
Winemaking in conditions without exposure of the wine to oxygen. The opposite of aerobic, which is a chemical process that takes place in the presence of oxygen. Wine aging in a sealed wine bottle is going through anaerobic aging. 
Anthocyanin
Phenolic pigments that give red wine its color.
Antioxidant
Chemicals, such as sulphur dioxide, ascorbic acid, others that are added to the grape must to prevent it from oxidizing.
Aroma
The scent of wine that is tasted. Refers to the primary smell characteristics of wines from grapes, herbs, fruit, flowers, spices etc.
Ascorbic Acid
An antioxidant added to grape must during winemaking to prevent it from oxidizing.
Assemblage
The blending of two or more different batches of wine by winemakers to produce a consistent finished wine that is ready for bottling. 
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B-B-B

Back-Blend
Blending fresh unfermented grape juice into a fully fermented wine in order to add more sweetness.
Balling Scale
The Balling Scale (or simply “°Balling”) is a measurement of dissolved sucrose level in a wine. The concentration can be measured most simply by using a hydrometer, an instrument used for measuring the specific gravity of a liquid.
Barrel Fermented
Wine fermented in wooden barrels as opposed to stainless steel or concrete tanks. Traditionally white burgundies, some chardonnays and some champagne are barrel fermented.
Barrique
A 225 liter (59 gallon) wine cask.
Bentonite
A type of wine clarifying agent made from clay of volcanic origins.
Blanc de Blancs
French for literally “white of whites”. Champagnes made exclusively from white skinned grapes, often Chardonnay.
Blanc de Noirs
French for literally “white of blacks”.  Champagnes made exclusively from dark skinned grapes, often Pinot Noir.
Blending
The mixing of two or more different batches of wine by winemakers to produce a consistent finished wine that is ready for bottling. 
Blue Fining
Largely obsolete use of potassium ferrocyanide to remove iron or copper casse from a wine. VERY DANGEROUS and environmentally unsound process.
Blush Wine
A pale, pinkish color wine made from red grapes that are removed early in fermentation. Commonly refers to rosé or white zinfandel.
Body
Taken as a whole, a wine’s consistency, thickness, mouth-filling properties and sensation of palate fullness ranging from thin to full-bodied.
Botrytis (Botrytis Cinerea)
Literally, “Noble Rot”, botrytis cinerea is a fungus that shrivels and decays wine grapes. Grapes that have been rotted by botrytis cinerea have increased sweetness and complex flavors. Commonly used for desert wines like sauternes and rieslings.
Bouquet
Taken as a whole, a wine’s aromas, fragrance, smell, odors or scents.
Brettanomyces
Brettanomyces is a non-spore forming single cell genus of yeasts in the family Saccharomycetaceae. It is often colloquially referred to as “Brett”. The genus name “Dekkera” is typically used interchangeably with “Brettanomyces” to  describes the single cell spore forming varieties of the yeast. In winemaking it is typically a wild yeast that causes wine spoilage and wine flavor defects commonly described as “farm house”, “barnyard” or “sweat socks”.
Brix
A measurement of the dissolved sucrose level in a wine as the percentage of sugar by weight in the wine. The concentration can be measured most simply by using a hydrometer, an instrument used for measuring the specific gravity of a liquid. See Balling Scale
Brut
A French term for the very driest Champagnes or sparkling wines. Drier than extra dry.
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C-C-C

Cap
The layer of grape skins on the top of the fermentation vessel that are forced to the top by rising carbon dioxide gas during fermentation.
Carbonic Acid
H2CO3. Carbon dioxide gas dissolved in water. 
Carbonic Gas
CO2. Carbon Dioxide. The gaseous by-product produced when yeast eats carbohydrates producing nearly equal parts ethyl alcohol and carbon dioxide gas. While a small amount stays presence in the wine as carbonic acid, most of the gas rises to the surface of the fermentation vessel. If the fermentation vessel is open the gas escapes into the air. If the fermentation vessel is closed (such as a sealed wine bottle), the gas will dissolve back into the wine resulting in champagne or sparkling wine.
Casein
A fining agent, potassium caseinate, derived from a milk protein. 
Cask
A wooded barrel typically made from oak that is used in winemaking for fermentation and/or aging
Cellaring
Storing wine in cellars. Can be simple storage or aging wine to improve it.
Centrifugal Filtration
Spinning a tank to use centrifugal force to separate unwanted particles such as dead yeast cells, fining agents, etc.
Ceramic Filtration
Slow process that filters wine through perlite – a clay-like filtering agent similar to diatomaceous  earth – to produce ultrafine wine.
Chaptalization
Adding sugar the must to increase the alcohol content in the fermented wine. This is often done when making wine from grapes that have not ripened adequately.
Charmat Method
Producing sparkling wine with secondary fermentation in a sealed tank as opposed to the traditional method where secondary fermentation takes place in the individual wine bottles.
Clarification
Fining and filtering wine to remove suspended solids and make the wine clear.
Closed Top Fermenter
Closed top wine fermenters are used for non-oxidative wine fermentation. Ideal for white wines, while fermenting the tank top remains sealed and an inert gas like nitrogen is used to fill any headspace in the tank and displace the oxygen. Wines produced this way have a clean, fresh taste and are perfect for early drinking.
Cloying
A wine taste defect with a sticky or sickly sweet character that is not properly balanced with acidity.
Cold Stabilization
A winemaking process where wine is chilled to near freezing temperatures for several weeks to encourage the precipitation of solids from the wine.
Color
From pale white to inky black, one of the most easily recognizable characteristics of wines. Used in the tasting analysis and classification of wines.
Crossflow Filtration
High-speed microfiltration tecnique that fast flows the wine across a membrane filter rather than through it.
Crush
1) Between harvesting from the vines but before pressing to extract juice, grapes are “crushed” or so that the juice is released and allowed to macerate with the skins prior to and during fermentation.
2) A term synonymous with harvest time in the wine country.
Cryoextraction
The process of freezing grapes artificially with refrigeration and then pressing them. Winemakers subject harvested grapes to freezing temperatures then press them while still frozen. Ice crystals remain in the press, while concentrated juice flows out. This production method is used to make so called “ice box wines” which are similar to true ice wines produced from grapes naturally frozen on the vine before harvest. 
Cut, Cutting
1) Blending wines with one distinct dominant characteristic (such as high acidity) into another wine that with a different dominant characteristic (such as low acidity). It can also mean blending red wine and white wine to make a rosé. 
2) May also refer to the illegal practice of diluting a wine with water. 
Cuvée
1) Term derived from French cuve, meaning “tank” or “vat”. A wine blended from several vats or batches, or from a selected vat. 
2) May also refer to Champagne fermented from the juice of the first pressing of a specific batch of grapes.
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D-D-D

Debourbage
The process in which the must of a white wine is allowed to settle before racking the wine to reduce the need for filtration or fining.
Délestage
French term for racking to remove harsh grape seed tannins from the wine. The wine is drained into a secondary vessel so  the cap settles to the bottom to loosen the seeds that are trapped in the grape pulps. As the wine is drained from the tank a filter captures the seeds and removes them from the wine. The wine is then returned the first vessel.
Depth Filtration
A process in which wine moves in a perpendicular flow towards the filter so that the clean wine passes through after particles get captured within the filter. These particles build-up, causing pressure in the filter to increase and flow rate to decrease. Once the filter reaches a saturation point the filter must be cleaned before the process can continue. Different forms of depth filters used for making wine include cartridge, pressure leaf, plate and frame and lenticular, among others.
Devatting
The process of separating red must from grape pomace either before or after fermentation.
Diatomaceous Earth
Very fine particles of sedimentary rock used for filtering wine.
Disgorgement
The removal from bottles of  sediment from secondary fermentation.
Dry
Wines with zero or very low levels of residual sugar. The opposite of sweet wines with high levels of residual sugar.
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E-E-E

Esters
Volatile organic compounds that form during fermentation through the interaction of acids with alcohols and which contribute to the fruity aroma and flavor of wine.
Ethanol
Ethyl alcohol. The colorless primary alcohol constituent of beer, wine and other distilled spirits.
Extract
The solid compounds found in wine. Higher levels of extract result in more color and body, which may be further increased by prolonging a wine’s contact with wine skins during fermentation.
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F-F-F

Fault
An unpleasant flavor or aroma of wine resulting from a flaw with the winemaking process or storage conditions. Often synonymous with “Defect” or “Flaw”.
Fermentation
The chemical conversion of fermentable sugars by yeast cells into approximately equal parts of ethyl alcohol and carbon dioxide gas.
Fermenter
Fermenters are specialized tanks designed to precisely control temperature and maintain the optimal conditions for wine fermentation; fermenters can be a variety of capacities with open and closed tops for easier winemaking.
Filtration
The removal of unwanted particles suspended in wine or grape juice.
Fining
Fining is used to clarify and stabilize a wine by adding a fining agent such as gelatine, isinglass, egg whites, casein, skim milk, bentonite, carbon, polyvinylpolypyrrolidone (PVPP), among others to the juice to coagulate or absorb and quickly precipitate the particles such as yeast, proteins or tannins suspended in the juice.
Fining Agent
A fining agent is a special material added to the grape juice to coagulate, absorb or quickly precipitate particles suspended in the juice. Some of the most commonly-used fining agents for wine are gelatine, isinglass, egg whites, casein, skim milk, bentonite, carbon, polyvinylpolypyrrolidone (PVPP), among others.
Finish
Refers to the sense and perception of the wine remaining on the palate after swallowing.
First Press
The first press, after the free run grape juice has been collected, that contains the clearest and cleanest grape juice that will come out of a pressing.
Fixed Acid
The acids involved with wine which do not evaporate readily. The predominant fixed acids found in wines are citric, malic, succinic and tartaric.
Fixed Acidity
A measurement of “total acidity” (TA), including citric, malic, succinic and tartaric acid present in a wine.
Flash Pasteurization
Also call “High Temperature, Short Time Pasteurization” or “Flash Détente”, is a pasteurization process where the wine is subjected to high temperatures around 160° F (72° C) for intervals of 30-60 seconds then rapidly cooled.
Fortification
The process of adding pure alcohol to a wine to increase the wine’s alcohol content. Depending on when the alcohol is added, either before, during or after fermentation, this can result in a wine with a high alcohol content and noticeable sweetness.
Free Run
Juice obtained from grapes that have not been pressed.
Fruit Wine
Fermented alcoholic beverages made from non-grape fruit juices which may include the addition of sugar or honey. Fruit wines are always called “fruit” wines (e.g., plum wine), since the word “wine” alone is often legally defined as beverages made exclusively from grapes.
Fully Fermented
Wine allowed to naturally complete the process of fermentation without interruption to produce wines that are completely dry.
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G-G-G

Gelatine
A fining agent used to remove excessive amounts of tannins and other negatively charged phenolic compounds from the wine.
Geosmin
A naturally occuring chemical compound found in wine grapes, beets, potatoes, and other vegetables that is responsible for some earthy aromas and flavors. 
Grape Juice
Free-run or pressed juice from grapes. Unfermented grape juice is known as “Must.”
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H-H-H

Hogshead
A large wine barrel that holds 63 gallons (238.7 liters).
Hydrogen Sulphide
Combination of hydrogen and sulphur dioxide which can produce a wine aroma defect reminiscent of the smell of rotting eggs.
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I-J-K

Isinglass
A fining agent used to remove tannins and other compounds from the wine.
Juice
Liquid which is extracted from grapes, fruit or vegetables.
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L-L-L

Lactic Acid
Lactic acid is an organic acid that is one of the principle acids in wine. During wine fermentation malolactic fermentation (MLF) is monitored by measuring level of L-malic acid and L-Lactic acid. Lactic acid helps provide a smoother flavor by reducing the acidity of wines.
Lactic Acid Bacteria
A bacteria which can cause wine aroma and flavor defects by excess malolactic fermentation. This can cause undesirable changes in wine flavor rendering the wine undrinkable with the smell of sauerkraut or pickles.
Lees
Wine sedimentary solids that occur during and after fermentation, and consist of dead yeast, grape seeds, and other solids. Wine is separated from the lees by racking.
Lifted
A wine that is particularly aromatic and pungent. 
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M-M-M

Maceration
Allowing grape skins to stay in contact with the must during fermentation to extract phenolic compounds including tannins, anthocyanins, and aroma.
Madeirized
A wine with a heavy Madeira-like flavor, generally evidence of excess oxidation. Sometimes used to describe white wine that has been aged long past its prime.
Malic Acid
A strong tasting acid in with the flavor of green apples. The amount of malic acid in grapes is gradually reduced naturally during ripening while the grapes are on the vine and can be further reduced during winemaking by fermentation and malolactic fermentation.
Malolactic Fermentation
MLF. A secondary fermentation in wines using lactic acid bacteria during which tart tasting malic acid is converted to softer tasting lactic acid.
Marc
The skins and seeds that remain after making wine. Also called “Pomace”.
Mead
An alcoholic beverage made of fermented honey, water and sometimes herbs and spices. A distinct beverage, mead is more akin to beer than to wine.
Membrane Filtration
Filtration by forcing liquids through a thin screen perforated with microsize holes that capture particles larger than the size of the holes.
Mercaptans
Chemical compounds formed by the reaction of ethyl and methyl alcohol with hydrogen sulphide to produce a sulpherous wine aroma defect reminiscent of rotten eggs, burnt rubber, etc.
Microvinification
Winemaking technique for making experimental batches of wine fermented in small, specialized vats.
Mistelle
Fresh grape juice that has been fortified with additional alcohol before fermentation. Generally results in sweet wines.
MOG
Winemaking slang for “Material Other than Grapes”. Usually refers to debris like leaves, dirt, twigs and stems that are unintentionally harvested with the grapes.
Must
Unfermented, unfiltered grape juice, including grape pips (grape seeds), skins and stalks.
Must Weight
A measure of the amount of fermentable sugar in grape juice (must) indicating the amount of alcohol that could be produced if it is all the sugar was converted to ethanol.
Mutage
Fortifying a wine by adding alcohol to the must either before, during or after fermentation.
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N-O

Neutral
A wine or spirit that has no specific flavor. Pure alcohol or pure alcohol dilted with water are flavor neutral.
Oak
The most commonly used hardwood for fermentation vessels and aging barrels. Oak influence can also be imparted to a wine by the used of oak chips or staves.
Oenology
The art and science of wine and winemaking.
Off-Dry
A wine with just the barest hint of sweetness; a slightly sweet wine in which the residual sugar is barely tasteable.
Open Top Fermenter
Open top wine fermenters are used for oxidative wine fermentation. Used primarily for red wines, while fermenting the open top gives the winemaker access to the “cap” which is formed from the wine skins on the top of the tank as the wine ferments. The winemaker, using a paddle can gently stir the cap back into the wine in the tank.
Orange Wine
A type of white wine made by leaving the grape skins and seeds in extended contact with the juice similar to red wine production, creating a deep orange-hued finished wine.
Organic Winemaking
Winemaking using only organically grown grapes and minimum amounts of chemical additives.
Osmotic Pressure
In winemaking, osmotic pressure is observed in yeast cells added to grape must with a high sugar content. The water in the yeast cell escapes through the cell membrane into the must causing the cell to cave in on itself and die (plasmolysis).
Oxidation
Chemical reaction of reagents with oxygen. Oxygen is one of the most reactive of all chemicals. Exposure to oxygen plays a vital role in wine fermentation and the wine aging process. But excessive amounts of oxygen can produce wine aroma defects and if exposed to air too long, a wine can become oxidized to the point that the wine turns to vinegar.
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P-Q

Pad Filitration
Filtering wine by running the wine through a series of pads made of asbestos, cellulose or thin sheets of paper.
Palate
The areas on the inside of your mouth associated with how foods or beverages taste to you.
Pasteurization
Pasteurization is the process of heating a substance, usually a liquid, to a temperature high enough to kill any microscopic organisms contained in it. Typically, the wine is heated to 185°F (85°C) for a minute, then cooled to 122°F (50°C), at which temperature it remains for up to three days, killing all yeast and bacteria. 
Pectic
An enzyme added to fruit to increase the juice yield. Also added to wine or must as a clarifying agent in fruit wines.
Perlant
A very lightly sparkling wine.
Perlite
A fine, powder-like substance of volcanic origins that is sometimes used for ceramic filtration. It has many of the same filtering properties as diatomaceous earth.
Phenols
Phenols are a broad class of chemical compounds which are by-products of fermentation and which are detectable in both the aroma and taste of finished wine. Phenolic flavor and aromatic attributes include cloves, herbs, medicines and others. Some phenolic flavors and aromas such as anthocyanins which impart color and tannins which add texture and aging potential are acceptable or even desirable in small concentrations. Higher concentrations of phenols in wine are a taste defect often due to contaminated water, infection of the must by bacteria or wild yeasts, inadequate cleaning and rinsing of equipment, etc. 
PolyVinylPolyPyrrolidone (PVPP)
PVPP is a synthetic polymer clarifying agent that can be used to reduce the level of phenolic compounds associated with astringency in wines.
Pomace
The grape skins and seeds that remain after wine has been made from must. Also called “Marc”.
Potable Alcohol
Another term for ethanol or ethyl alcohol which accounts for the majority of alcohol compounds found in wine
Potassium Sorbate
Odorless and tasteless chemical salt commonly used as a wine stabilizer and preservative.
Potential Alcohol
The calculation of the potential finished alcohol levels if a batch of grape must was fermented to complete dryness. See Biix.
Pre-fermentation Maceration
The time that the grape must spends in contact with its skins prior to fermentation. This technique may enhance characteristics of the wine and leech important phenolic compounds out from the skin. This process can be done either cold or warm temperatures.
Proof
Refers to the alcohol content of a beverage. In the United States, proof represents twice the alcohol content as a percentage of volume. Thus, a beer that is 3.2% alcohol by volume is 6.4 proof, a wine that is 14% alcohol by volume is 28 proof, a 100 proof beverage is 50% alcohol by volume, a 150 proof beverage is 75% alcohol by volume, etc. 
Protein Haze
Condition with excessive amounts of protein particles suspended in the wine. These proteins react with tannins to create a cloudy, hazy appearance in the wine. This condition is corrected by using fining agents, such as gelatine, isinglass, egg whites, casein, skim milk, bentonite, carbon, polyvinylpolypyrrolidone (PVPP), among others, to remove the proteins.
Pyrazines
A group of aromatic grape compounds that contribute green herbaceous notes a wine such as the hints of green bell pepper found in some Cabernet Sauvignons. An abundance of pyrazines can be a sign that the grapes were harvested from vines with dense leaf cover that impeded the ripening process of the grapes.
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R-R-R

Racking
“Racking” literally means moving wine from one vessel to another. This can be from a tank to a barrel, one barrel to another barrel, or a barrel to a tank. This separates the wine from the skins, seeds, dead yeast cells, and other particles that settle to the bottom of the source vessel.
Remontage
The process of pulling wine from underneath the cap of grape skins and then pumping it back over the cap in order to stimulate maceration.
Residual Sugar
Unfermented sugar remaining in the wine after fermentation has ended. All wines contain some residual sugar due to the presence of unfermentable sugars in the grape must.
Reverse Osmosis
Passing wine through an osmotic filter to remove excess water and/or alcohol.
Rosé Wines
Blush wines produced by shortening the contact period of red wine juice with its skins, resulting in a light red/pink color. These wines can also be made by blending a small amount of a red wine with a white wine.
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S-S-S

Saccharometer
A hydrometer that uses specific gravity to measure the sugar content of grape juice. See Hydrometer.
Sec
French for “dry”, except for Champagnes, where it means “semi-sweet”.
Secondary Fermentation
The continuation of fermentation in a second vessel – e.g. moving the wine from a stainless steel tank to an oak barrel.
Skin Contact
See Maceration.
Sorbic Acid
An acid added to wine in order to halt yeast activity and alcohol production – typical in the production of sweet wines.
Sparging
Wine sparging is where a selected gas (typically nitrogen although argon and carbon monoxide may also be used) is bubbled into the wine to remove dissolved oxygen. This process helps minimize harmful oxidation and ensure the production of high-quality wine. (Distinctly different from “Beer Sparging” which involves spraying hot water over the spent mash grains to recover any remaining liquid malt sugar and extract from the grain husks.)
Stabilization
The process by which insoluble matter suspended in the wine is removed before bottling. Stabilization may involve a combination of fining, filtration, centrifugation, flotation, refrigeration, pasteurization, and/or barrel maturation and racking.
Stabilizer
An additive which is added to wines before they are sweetened. Stabilizers prevent re-fermentation by disrupting the reproductive cycle of yeast rather than stopping fermentation by killing the yeast. 
Still Wine
Wine that is not carbonated.
Stoving Wine
Artificially mellowing wine faster than natural aging using heat.
Stretching
Cut or dilute a wine with water to lower the alcohol level of the wine. 
Stuck Fermentation
Fermentation that has halted prematurely. A wine process defect due to yeast becoming dormant or dying, causes for stuck fermentation including excessively high fermentation temperatures, yeast nutrient deficiency, excessively high sugar content, among others.
Sulphites
Sulfites (typically potassium metabisulfite or sodium metabisulfite) are food preservatives widely used in winemaking to maintain the flavor and freshness of wine. While sulfites are found in many foods and beverages, they’re particularly associated with a long list of side effects related to wine, including the unpleasant next morning wine-induced headache.
Sulphur Dioxide
A sulfer compound used in winemaking as an antioxidant and preservative. Too much can result in a wine aroma defect smelling of sulphur, rotten eggs or burnt matches.
Supple
A wine that is soft, smooth and well-balanced. Wine that is not overly tannic.
Süssreserve
A reserve of unfermented grape juice that is added to wines as a natural sweetening device.
Sweetness
Sweetness is the measured level of residual sugar in the final grape juice after fermentation has ceased. However, how sweet a wine will actually taste is also affected by acidity, alcohol level, the amount of tannin present, whether the wine is fortified, whether the wine is sparkling, etc.
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T-T-T

Tank Method
Producing sparkling wine with secondary fermentation in a sealed tank as opposed to the traditional method where secondary fermentation takes place in the individual wine bottles. See Charmat Method.
Tannin
Phenolic compound derived from the skins, seeds (pips) and stalks of grapes that gives wine a bitter, dry, or puckery feeling in the mouth. Tannins also act as a preservative and anti-oxidant.
Tartaric Acid
Tartaric acid is one of three naturally occurring acids present in wine grapes (the other two are Malic acid and Citric acid). Tartaric acid plays a large part in a wine’s “tart” sensation on the palate.
Tartrate Crystals
Tartaric crystals form from crystallized deposits of tartaric acid salts that can be found in the bottom of wine bottles or on the wine corks when they precipitate out of the wine over time or when the wine is exposed to cold temperatures during cold stabilization.
Terpene
Terpenes are a large class of organic compounds produced by plants that are the main components responsible for the characteristic floral and fragrant aromas in some grapes and wines. 
Téte de Cuvée
Literally French for “Top of the Batch”.  Wine made from the very first pressing of the grapes. After the free run grape juice, this is the highest quality grape juice from a batch.
Titratable Acidity
The measure of the amount of acidity for the total of all acids present in a wine while strength of acidity is measured according to pH. Most wines having a pH between 2.9 and 3.9, with the lower the pH, the higher the acidity in the wine. Also called Total Acidity.
Topping
The process of preventing wine oxidization by adding additional wine to fill the headspace to replace wine that evaporates during aging.
Total Acidity
Total Acidity (also known as the “titratable acidity”) is the measure of the amount of acidity for the total of all acids present in a wine while strength of acidity is measured according to pH. Most wines having a pH between 2.9 and 3.9, with the lower the pH, the higher the acidity in the wine. Also called Titratable Acidity.
Triage
Sorting and grading of grapes after harvest but before crushing to remove less desirable bunches of grapes.

U-V

Ullage
The unfilled space in a wine bottle, barrel, or tank. To prevent oxidization this space may be filled by adding additional wine. See Topping.
VA Lift
Deliberately elevating the volatile acidity of a wine to enhance the fruitiness of wines meant to be consumed young.
Vacuum Distillation
Removing water from grape must at a lower temperature than standard distillation and boiling which can also burn off the wine’s delicate flavors and aromas. Within a sealed tank the pressure on the liquid is gradually reduced allowing the must to boil at between 77 °F (25 °C) to 86 °F (30 °C) which causes much less damage to the wine. This technique is sometimes used when late harvest rains have caused the grapes to swell with water, potentially diluting the flavor and alcohol level of the wines.
Vanillin
A fragrant compount found naturally in oak that can impart a trace of vanilla aroma to wine aged in oak barrels.
Variable Capacity Fermenter
Variable capacity wine fermenters can be used for both oxidative and non-oxidative wine fermentation. A “variable capacity” wine fermenter is essentially an open-top wine fermenter fitted with a sliding lid that can slide up and down the tank to accommodate variable sized batches of wine or the lid can be removed so that the fermenter becomes an open-top fermenter. 
Varietal
A wine made from a single grape variety. Popular varietals include Cabernet Sauvignon, Pinot Noir, Riesling, Pinot Grigio, Chardonnay and many more.
Vinegar
A sour-tasting, highly acidic liquid made from the oxidation of ethanol in wine, cider, beer, fermented fruit juice, or nearly any other liquid containing ethyl alcohol.
Viniculture
The art and science of making wine. Also called “enology” or “oenology”.
Vinification
The process of making wine from grapes. Winemaking.
Vinimatic
An specialized fermentation tank which uses rotating paddles to maximize grape juice extraction during maceration while minimizing the potential for oxidation.
Vinous
A wine that tastes of grapes, displaying no varietal fruit or winemaking characteristics.
Volatile Acidity

VA. Volatile acidity refers to the steam distillable acids present in wine, primarily acetic acid but also lactic, formic, butyric, and propionic acids. These acids are detectable on both the nose and the palate. Commonly, these acids are measured by gas chromatography or enzymatic methods. Excessive volitile acidity is  considered a wine flavor or aroma defect.
Volatile Phenols
Phenolic compounds found in wine that may contribute to off odors and flavors that are considered defects. The most common types of volatile phenols found in wine are ethyl and vinyl phenols. To a limited degree some volatile phenols contribute pleasing aromas that add to a wine’s complexity.
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W-X-Y-Z

Wine
An alcoholic beverage made from the fermentation of grapes or other fruit juices.
Wine Cave
A large cave that provides a naturally cool, dark location in which barreled or casked wine is stored and aged.
Wine Cellar
A cool, dark location, often in the basement of a building, in which bottled wine is stored and aged.
Wine Fault
Undesirable wine flavors or aromas caused by poor winemaking techniques, contamination or improper storage conditions. Also “Wine Defect” or “Wine Flaw”
Wine Press
A device for crushing grapes and collecting the juice.
Wine Fermenter
Fermenters are specialized tanks designed to precisely control temperature and maintain the optimal conditions for wine fermentation; fermenters can be a variety of sizes with open and closed tops for easier winemaking.
Wine Tote
An open-topped utility tank used to temporarily store grapes or wine. Can also be used as an open top wine fermenter.
Winemaker
A person engaged, either professionally or on an amateur basis, in the occupation of making wine.
Winery
A building, property, or company that is involved in the production of wine.
Wood Lactones
Aromatic esters that a wine picks up from exposure to new oak barrels. These lactones are responsible for the rich creamy and coconut aromas and flavors that develop in a wine.
Yeast
Living single cell organisms that convert sugars into alcohol and carbon dioxide gas during fermentation. Yeast is vital for the fermentation process. They also provide fizz and are necessary in the bottle to build natural effervescence.
Yeast Enzymes
Enzymes within yeast cells that each act as a catalyst for a specific activity during the fermentation process. There are numerous yeast enzymes that are known to be active during the fermenting of wine.
Zymurgy 
The study or practice of fermentation in brewing, winemaking, or distilling.
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Portland Kettle Works (“PKW”) is the premier American manufacturer of stainless-steel brewing and beverage equipment for Craft Beer, Wine, Kombucha, Cold Brew Coffee, Pharmaceutical and Dairy applications plus Mixing Tanks, and accessories for these industries.




Portland Kettle Works was founded in 2011 to build the highest quality stainless steel brewing and beverage equipment applications. Since then we have built and installed over 300 breweries worldwide. Our craft brewers are among the best of the best and they have the gold, silver and bronze medals to prove it. If you’re serious about craft brewing as a business, contact us and we can help you, too. And if you’re located in Mexico or Latin America, click here to visit our Spanish language site.