A glossary is an alphabetical list of the specialized terms used in a field of knowledge. Kit winemaking is pretty specialized. No matter how widespread it seems to get there’s always a bunch of people in any group who are stunned to find out you can make your own wine so easily. Some of this stuff may be obvious to old hands, but there is a real benefit to reading glossaries of things you already know, both to keep yourself sharp, and to laugh at the author’s opinions.
ABV: Alcohol by Volume. Usually between 11% and 13.5% in dry table wines made from kits.
Acetic: A term for the odor or flavor of vinegar (Acetic Acid). Considered a flaw in wine and beer
Acetobacter: Bacteria that can attack wine to cause acetification—the conversion of wine to vinegar - through the production of Acetic Acid.
Acid: Grape juice contains a mixture of fruit acids (tartaric, malic and citric). They help balance the flavour of the wine with fruit character and residual sugars. Your kit may be adjusted with extra acid, both to keep the pH low and to balance a sweetened wine.
Ageing: A complex series of chemical reactions, both in the carboy (bulk aging) and the bottle, which combine components in the wine to combine to produce new flavors. Some carboy ageing can be beneficial, but the most controlled and safest place for wine ageing will always be in the bottle, under a good quality cork.
Airlock and Rubber Bung: Together they form a one-way valve that seals the carboy at the neck. Some primary fermentation buckets also have an airlock port. Prevents oxygen and spoilage organisms from entering and allows fermentation gases to escape.
Alcohol: The by-product of fermentation wherein the yeast metabolizes sugar in roughly equal parts of carbon dioxide and ethanol.
Anthocyanins: The red or purple pigments in grapes that make wine red
Aperitif: Wine that is usually drunk by itself or before a meal in order to stimulate the appetite. Dry Sherry and vermouth are traditional aperitifs.
Atmosphere: Technical term for pressure in a wine bottle. Average internal pressure in sparkling wine is 6 atmospheres.
Attenuation: The degree to which yeast consumes the available sugar in wine or beer during fermentation, represented as a percentage. An attenuation of 100% is generally desired in most wines, while a lower attenuation percentage is typical for beer, mead, or sweet wines to leave some sweetness in the finish
Autolysis: The breakdown of dead yeast cells (lees). While autolysis is sometime encouraged in winemaking, it’s usually avoided in kits by early racking from sediment and finings.
Balling: An older measure for representing the specific gravity of wine, but still used in some parts of the world. Very similar to Brix and Plato, it can be used interchangeably with those scales. see Brix below
Bentonite: A fining (clearing) agent made from a type of clay (Montmorillonite, a naturally occurring hydrated aluminosilicate of sodium, calcium, magnesium, and iron.) Fining agents clear wine by removing proteins, colloids and dissolved and suspended materials from solution. Also added to a clear juice at the beginning of a fermentation to provide yeast nucleation sites and speed the onset of fermentation. 5 ml (one teaspoon) weighs approximately 3 grams.
Bergamais: Ber-ga-may". A Canadian Home Wine Trade Association (CHWTA) trademarked name used in replacement of Beaujolais. Medium-red in colour with forward fruit and cherry notes, it is ready to drink sooner than many other reds, and isn’t a good candidate for long-term ageing.
Blind Tasting: Tasting and evaluating wine without knowing what it is. A very useful practice for winemakers, as it removes prejudices and expectations from the tasting environment.
Blush: Pale, pinkish-colored wine. May refer to a sweet rosé such as White Zinfandel.
Bottle: A small container with a neck that is narrower than the body. Most wine bottles are made of glass because it is nonporous and visually pleasing—it keeps air out and you can see inside. Bottles come in a variety of shapes and sizes, but the most common is 750 ml (25.6 ounces) in volume, and a standard 6 US-gallon (23 litre) kit will require between 28 and 30 bottles when finished. Screw-top bottles are currently unsuitable for home winemaking because the machinery required to put a new top on is prohibitively expensive.
Bottle Age: Time that wine has been allowed to mature in bottle.
Bottle Shock: Freshly bottled wine is not only highly agitated by the filling and corking process, but also contains quite a bit of unbound oxygen. This shows up as a muted aroma, flat taste and dull character compared to the wine just before bottling. It usually disappears after a few weeks but may be present for longer. Also known as bottle sickness.
Breathing: Wine is an ongoing chemical reaction. When a bottle is opened, the interaction between air and wine will modify flavors and aromas. Young kit wines often benefit significantly after breathing for an hour or more, but very old wines may fall apart completely soon after exposure to oxygen. Breathing requires decanting—pulling a cork from a bottle exposes too little surface area of the wine for it to pick up much oxygen.
Brix: This is the percentage of sugar by weight in grape juice. For example, 25 Brix is 25% sugar. Most kit manufacturers use SG (Specific Gravity) but some commercial wineries and most textbooks use Brix. Also referred to as Degrees Brix. Often measured using a Refractometer.
Bung: Cone-shaped rubber or silicone plug, usually with a hole through the cone’s axis to accommodate an airlock. Fits tightly into the neck of a carboy to keep out air, dust and organisms.
Campden Tablet: Source of SO2 (sulphur dioxide) in wine making. Unless identified, Campden tablets are the sodium form of metabisulphite. It kills certain bacteria and inhibits most wild yeast. It also prevents oxidative spoilage by binding to free oxygen in wine and grape juice. This binding effect also eliminates free chlorine from water solutions (i.e., tap water).
Cap: The solid material (skins, seeds, pulp) that floats to the surface of wine during fermentation when using fresh grapes or fruit. To help discourage mold growth, winemakers can punch down this material daily using a sanitized spoon.
Capsule: A plastic or foil dressing that covers the top of the cork and partway down the neck of a wine bottle. Purely decorative, they don’t extend or impair wine ageing in any way.
Carbon Dioxide (CO2): The byproduct gas released by yeast during fermentation. CO2 in the fermenter helps protect the wine from damaging oxygen. However, a bung and airlock must be used to prevent dangerous pressurization of the fermenter; allowing excess CO2 to escape. Degassing wine during racking helps to drive off CO2 before bottling still wines. The deliberate addition of yeast and sugar at bottling is used to create sparkling wines and champagne.
Carboy: A bottle-shaped container made of glass or plastic. The most common sizes are 23 litres (6 US gallons) and 11.5 litres (2 US- gallons). Glass is easy to clean and sanitize, provides an impermeable barrier to oxygen and its transparency makes checking on the progress of clearing very easy. Newer PTFE plastic carboys have many of the advantages of glass without the danger of breakage, and are much lighter.
Cellaring: Storing wine in a controlled environment, usually to improve it through age.
Chaptalization: Adding sugar to grape juice to increase the alcohol content in the finished wine. Used in kits to force alcohol content higher after fermentation has begun.
Chloriclean: See Diversol BX/A
Chitosan (kite-oh-san): A fining agent. Technically an acetylated glucosamine polymer closely related to cellulose (wood fibre). Although people with shellfish allergies may be alarmed at the source of Chitosan (chitin derived from the outer shells of ocean crustaceans) it has no allergenic properties. The shells are powdered and repeatedly treated with heated alkaline solutions to destroy all proteins: allergic reactions are caused by specific protein chains. Chitosan is protein free, is approved for dietary use, and is commonly used as a water treatment product.
Clarification: Process of fining and filtering wine to remove suspended solids and increase clarity.
Claro KC: Two-part liquid fining that uses colloidal silica and Chitosan in succession.
Cleaning: The physical action of removing dirt, visible residue or debris from equipment. Distinct from sanitizing, cleaning comes first.
Coates Law of Maturity: Defined by Master of Wine Clive Coates, it states that a wine will remain at its peak of drinking quality for as long as it took to reach that point. For example, if a wine peaks at 3 years of age, it will continue drinking at its peak for approximately 3 years.
Cold stabilization: Chilling grape juice or finished wine to freezing temperatures to precipitate of tartrate crystals. Kit manufacturers usually cold stabilize their juices before using them in kits.
Colloidal Silica (AKA: Kieselsol): Silicon dioxide. Fining agent made up of 30% silicon dioxide (the same stuff that makes up beach sand) in a water suspension.
Cork: Stopper made from the outer bark of the Quercus suber, the cork oak tree.
Cork taint: Undesirable aromas in wine attributed trichloranisole, a by-product of mold growth on corks that have been in contact with chlorine.
Corkscrew: A pointed metal helix attached to a handle, usually with a lever arm, for drawing corks out of bottles. While there are a lot of complicated models out there, the simplest ‘wine waiter’ corkscrews tend to last the longest.
Decanting: Pouring wine from its bottle into a decanter, either to separate the sediment from a very old wine, or to allow a young wine to breathe. Sediment decanters have bodies shaped more or less like a wine bottle, while breathing decanters have extremely broad bases, which fill only to their widest point when an entire bottle is poured in. This exposes the largest surface area of wine to oxygen, speeding the breathing process.
Degassing: Vigorous stirring or mixing of wine during the final stages of secondary fermentation in order to drive off excess CO2 in solution. This ensures the desirable stillness in most wines. Degassing can also be performed early in the fermentation of high gravity meads to help encourage yeast health by removing toxic levels of CO2. While a spoon can be used for degassing, specially designed degassing tools are often more effective, especially when used with an electric hand drill.
Dessert wine: Often sweet, these wines have either low alcohol contents (icewine-style) or high (Port, Sherry and late-harvest styles). US law defines any wine containing over 15% alcohol as dessert wine.
Diammonium Phosphate (DAP): A common component in yeast nutrient, DAP provides nitrogen essential to the yeast cells.
Diversol BX/A: Sanitizing detergent commonly used in Canada for home winemaking, it is an alkalized chlorine detergent with other additives. Equipment must soak for at least 20 minutes to achieve sanitation, and then be rinsed thoroughly with hot water. Alkaline solutions should not be mixed with acids, amines, ammonia, or reducing agents, which release heat and chlorine gas, or used with stainless steel due to corrosive pitting.
Dry: Wine with zero or very low levels of residual sugar. The opposite of sweet.
Elderberries: Additive in some kits, the dried berries of the elderflower bush usually come from Belgium, although they do grow in all temperate climates. Adds tannin and ‘plummy’ flavor, along with reddish brown color, but the distinctive character is not appropriate to all wines.
Elderflowers: Additive in some kits, the dried flowers of the elderflower bush usually come from Belgium, although they do grow in all temperate climates. Adds floral and licorice notes to aroma. Usually used in dessert wines, Riesling or Gewurztraminer, the distinctive character is not appropriate for all wines.
Eiswein (Ice Wine): German word for Ice Wine, an extremely sweet dessert wine made from frozen grapes.
Esters: Aromatic chemicals formed in wine during fermentation or ageing that contribute to aroma. Generally perceived as fruity.
Ethanol (Ethyl Alcohol): The alcohol in alcoholic beverages. A byproduct of yeast metabolism produced during fermentation.
Extract: Solids left over when all the water, sugar, alcohol, and acidity are removed from wine. High levels of extract result in more color and body.
Fermentation: Conversion of sugar to alcohol and carbon dioxide by yeast.
Filtration: Mechanical removal of unwanted particles suspended in wine or grape juice.
Fining: Clearing wine through the addition various protein or mineral agents. Finings work through electro-chemical attraction, glomming on to solids in the wine and aggregating into clumps that fall to the bottom of the container.
Finish: The very last taste impression of wine or beer. Flavor, texture, and duration are all considered when evaluating the finish.
Fortified wine: Wine to which distilled alcohol has been added to increase the concentration to a high enough level to prevent fermentation. Kit wine manufacturers strive to make their fortified-style wines (such as port and sherry style) complete, and the instructions in those kits include sugar ‘feedings’, or additions of sugar to active fermentation to increase alcohol content without impairing yeast activity. Some winemakers choose to fortify their port and sherry style kits in any case.
Free Sulfur Dioxide (Free SO2): The measure of sulfur dioxide in the wine solution that is not already bound to other chemicals. While correct levels of SO2 can help protect wine from oxidation and spoilage, an excess of it may be perceptible and considered a flaw. see Potassium Metabisulfite below
French Oak Chips: See Oak Chips.
French Paradox: The low mortality rate from cardiovascular disease among the French, despite their high-alcohol, high-cholesterol and low exercise lifestyle. Contrasted to the high mortality rate among Americans with a lower cholesterol, low alcohol and higher exercise lifestyle, it was theorized in a 1991 episode of the news program ‘60 Minutes’ that it was red wine consumption that gave the French a ‘get out of infarction free’ card. It was a real boon to sellers of wine (and wine kits.)
Fruit wine: Alcoholic beverage made from non-grape fruit juice. Fruit wines are always named (e.g., blueberry wine), since the word wine is legally defined as a beverage made only from grapes. See also Mist wines.
Gelatine: The most powerful of the protein fining agents and too powerful for most wine kits. In excess it will remove color and flavor compounds from wine. Not commonly used today, it is still mentioned in the literature.
Glycerine (AKA: Glycerol): Some winemakers add glycerine to finished wine to add ‘fullness’ or ‘smoothness’, while others find it gives an unpleasant metallic taste. Glycerine cannot be removed from wine, so when in doubt add in small increments, or only add to a portion of the wine so it can be blended down if too strong. A better solution is to buy higher-value kits that don’t require glycerine additives.
Grape Skin Extract: Natural pigment derived from grape skins, used to make light-colored wine dark purple. It is impossible to remove from treated wine so when in doubt add in small increments, or only add to a portion of the wine so it can be blended down if too dark. Can make wine a garish purple, leave teeth stained and introduce a haze, and not all wines are supposed to be dark purple. A better solution is to buy kits that better suit your color preference.
Heating Belt: Low wattage electrical device that wraps around a primary fermenter or carboy to raise the temperature above ambient level of the fermenting area. Useful in winter or cold climates, as many wine kits require fermenting temperatures between 65°-75°F (18°C-24°C).
Hydrogen sulphide: Combination of hydrogen and sulfur which can produce a smell of rotten eggs. Rare in kit wine, it’s a sign of poor yeast metabolism.
Hydrometer: A hydrometer measures specific gravity (S.G.) and is very useful for monitoring the progress of fermentation. You should take (and record) a hydrometer reading at each step in your winemaking process, until your wine reaches its final gravity.
Isinglass: A positively charged collagen (protein) fining agent derived from the swim bladder of type of African cichlid fish. Extremely gentle, it is sometimes used in conjunction with other fining agents.
Juice: Liquid expressed from fruit or vegetable matter—such as grapes.
Kosher: Kosher wines must be produced only by observant Jews under the supervision of a Rabbi—this is why, although wine kits might qualify as a Kosher food product, getting it Kosher to the bottle is more difficult.
Late harvest: Wine made from grapes that have been left on the vine past the usual harvest time. Usually made into a sweet or dessert wine.
Lees: Sediment of dead and dormant yeast on the bottom of a fermenting vessel or barrel.
Litre: Standard unit of volume in Canada (where most of the major wine kit manufacturers are based). 33.8 fluid ounces, or just over a quart.
Magnum: Double-sized wine bottle holding 51.2 ounces (1.5 litres).
Malolactic fermentation (AKA: MLF): A secondary fermentation in wines by lactic acid bacteria which convert tasting malic acid into softer tasting lactic acid. Usually not recommended for wine kits (which would be spoiled by it).
Mead: A beverage made from fermented honey. Honey Wine. Long considered to be the original fermented beverage. Mead can be made sweet or dry, sparkling or still, and anywhere in between. Meads that include other ingredients are named: Cyser (apples), Melomel (fruit), Pyment (specifically grapes), Metheglin (spices and herbs), Braggot (malt).
Meritage: Trademarked term of the California wine industry, best summed up as ‘American Bordeaux’. The red must be a blend of at least 2 of the 5 Bordeaux red grape varieties: Cabernet Sauvignon, Merlot, Cabernet Franc, Petit Verdot, and Malbec. White is a blend at least 2 of Sauvignon Blanc, Muscadelle (called Sauvignon Vert in California) and Semillon.
Microoxygenation: Carefully controlled exposure of wine to minuscule amounts of oxygen, to shorten maturation times. Accomplished in wine kits by carefully managed racking times.
Must: The mixture of grape juice, water, and other ingredients before fermentation has begun. Once fermented, it is wine.
New World: Wine regions outside of the traditional growing areas of Europe and North Africa.
Nose: A wine’s smell, often referred to as aroma or bouquet. Note that old-school wine critics sometimes refer to all them smells derived from the grapes (fruit character, floral notes, etc) as aroma, and all of the smells derived from processing and fermenting (buttery, oaky, smokey, etc) as bouquet, but that's not in fashion anymore.
Oak Chips: Dried and chipped heartwood from American, French or other oak trees. Toasted to varying levels oak chips add wood, vanilla, butter and smoke notes to wine. Can be used before or after fermentation, depending on the kit.
Oak Powder: Dried toasted powder of heartwood from American, French or other oak trees. Oak powder’s advantage over regular oak chips lies in its use during primary fermentation, where flavors and aromas transfer very quickly and efficiently. Also improves early drinkability.
Off-dry: Slightly sweet wine in which the sugar is barely perceptible.
Old World: Wine regions of the traditional growing areas of Europe and North Africa.
Organoleptic: The sensory properties of foods or chemical components as sensed by taste, color, odor and feel.
Oxidation: Degradation of wine through exposure to oxygen.
Pasteurize: To heat grape juice to kill spoilage organisms such as bacteria, viruses, protozoa, moulds, and yeasts. Wine kits are treated by an HTST (high temperature, short time) process that rapidly heats the juice above 160°F and cools it with equal rapidity, to prevent the heat from burning or caramelizing the sugars.
Pectic Enzyme: Breaks down the naturally occurring pectin in grapes. Usually added at crushing to increase yield and improve clarity of the finished juice, it is deactivated in wine kits by the heat of the Pasteurizing process.
Pectin: A compound in fruit pulp that can contribute haze/cloudiness in fruit wines and cider. Can be reduced with the use of Pectic Enzyme.
Port: Fortified sweet dessert wine produced in the Douro region of Portugal. The addition of distilled grape spirits boosts the alcohol content, kills yeast and stops fermentation, preserving grape sugars. Legally, wine kits are labelled ‘Port Style’, and use various techniques to increase alcohol content without the need for fortification.
Potassium Metabisulfite: Stable crystalline salt of elemental sulphur, and a source of sulphur dioxide (SO2) in wine making. Suppresses bacteria and yeast and prevents oxidation and spoilage in finished wine. Mostly harmless.
Potassium Sorbate: Stable salt of sorbic acid used to prevent renewed fermentation in sweet wines. It inhibits reproduction of mold and yeast, but must not be added until all fermentation has ceased. Sorbate can be attacked by lactic bacteria in wine and converted to a compound with the strong and disagreeable odor of rotting geraniums. Lactic bacteria are easily inhibited by metabisulphite.
Primary Fermentation: The initial, vigorous stage of fermentation where the sugary must is combined with yeast. The bulk of fermentable sugars will be consumed during this stage. Takes place in the Primary Fermenter.
Primary Fermenter: Food-grade plastic container, with a cover. Should be at least 30% larger than your starting volume. For example a 6 US gallon (23 litre) kit will require a container of at least 7.9 gallons (30 litres).
Punt: The indentation in the base of a wine bottle. A feature intended to increase bottle strength, it is often assumed that better quality wines have a deeper punt. While not necessarily true, deeper punt bottles cost more, and so might only be used on higher-value wines.
Quaffing: A lot like drinking, but with more spilling and loud voices. Used to describe simple, everyday wines intended for casual consumption.
Racking: Transferring wine from one container to another, leaving sediment behind. Usually done via gravity, the vessel to be racked is elevated and a siphon rod immersed in it. A siphon hose connects them to an empty vessel below. Racking helps to clear wine, and may also be used to introduce small amounts of oxygen to the wine to assist in flavour development.
Redox: Short term for reductive-oxidative, the process by which wine ages. Part of the ageing and maturing process relies on the presence of oxygen, but when the wine is excluded from oxygen in the bottle it develops mature characteristics through reductive (non-oxygen using) reactions.
Refractometer: A device that instantly reads the specific gravity (in Brix) of unfermented wort or fruit juice by measuring the degree that light passing through the sample is bent. Unlike a hydrometer, only a few drops are required for a sample. To use, apply 2-3 drops to the prism face, close cover, and look through the eyepiece while aiming your refractometer at a light source. see Brix above.
Residual sugar: Level of sugar remaining unfermented in wine.
Reserve: Marketing term given to wine to signify that it is of higher quality.
Rosé: Pink wines produced by short contact times between red grape skins and juice. Also made by blending a small amount of red juice with white.
Sanitizing: The process of reducing the number of microbial contaminants and spoilage organisms on a surface or piece of equipment to a safe level. Sanitizing does not involve the complete destruction of any organisms—that is sterilization, and takes chemicals or processes unavailable to home winemakers. Sanitizing is distinct from cleaning—you can’t sanitize a surface that is not already clean (free of visible debris or residue).
Secondary Fermentation: The conditioning or aging stage of fermentation where the wine clears and stabilizes prior to bottling. Once fermentation has subsided, the wine is transferred (or racked) out of the Primary Fermenter into a Secondary vessel. The term Secondary Fermentation is somewhat of a misnomer as the actual fermentation is essentially complete and the racking process removes much of the yeast.
Secondary Fermenter: The vessel in which conditioning or aging occurs prior to bottling. Once the initial fermentation has subsided, the wine is transferred out of the Primary Fermenter into a Secondary Fermenter, usually a carboy. It is best to minimize contact with oxygen during this stage.
Sherry: Fortified wine made in the Jerez de la Frontera region of Spain. Primary character is rancio, the nut-like aroma and taste from controlled oxidation. Legally, wine kits are labelled ‘Sherry Style’, and use various techniques to increase alcohol content without the need for fortification.
Siphon Hose and Siphon Rod: 5 ft of food-grade tubing attached to a rigid acrylic rod. Used for transferring wine from one container to another while leaving sediment behind.
Sodium Metabisulfite: Stable crystalline salt of elemental sulphur, and a source of sulphur dioxide (SO2) in wine making. Suppresses bacteria and yeast and prevents oxidation and spoilage in finished wine. The US government currently bans the use of sodium metabisulfite in commercial wines due to health concerns over sodium intake. Mostly harmless.
Sommelier: Person who sells wine in restaurants.
Sparkalloid: Extremely potent positively charged fining agent made from crystalline silica, quartz aluminosilicate and cristobalite, suspended in a colloidal compound. Due to its strength it is only rarely used as a primary fining agent, as it can strip wine of desirable flavor and aroma.
Sparkling wine: Carbonated wine. Home winemakers usually achieve bubbles by adding sugar to finished wines, then sealing them in pressure bottles with a strong cork.
Specific Gravity (S.G.): Measurement of the density of juice or wine in relation to water. Used for tracking the progress of fermentation (as sugar is replaced by alcohol wine becomes less dense, the hydrometer sinks deeper into the liquid and gives a lower reading). Potential alcohol can be calculated from the starting s.g
Spoon: Needed for mixing and degassing wine kits. Should be made of food-grade plastic or stainless steel, approximately 28 inches (70 cm) long. Avoid wooden spoons as they can harbor micro-organisms.
Stabilization: Decreasing volatility of wine by removing material may cause chemical changes after bottling. In home winemaking this is done with fining, filtration, and adding stablizing chemical such as metabisulphite and sorbate.
Stuck: Fermentation that stops prematurely. There are a variety of possible causes including excessively high fermentation temperatures, nutrient deficiency or excessively high sugar contents.
Sulphites: Sulphur compounds added to wine to prevent oxidation and spoilage, and to prevent further fermentation.
Supertuscan: Premium quality Italian wine from Tuscany, produced outside of DOC regulations and sold for high prices with a vino da tavola designation. Usually Sangiovese, or Sangiovese/Bordeaux blend.
Sur lie: Ageing wine on its dead yeast cells for a prolonged period to increase mouthfeel and complexity. An advanced technique.
Süssreserve: Portion of unfermented grape juice added to wines after fermentation to sweeten them.
Table wine: Any non-sparkling, non-fortified wine between 7% and 14% alcohol by volume. Also used to describe unassuming, everyday wines for easy drinking.
Tannin: Bitter compound found in grape seeds, stems, and skins. Also extracted from wooden barrels and used to boost tannins in wines that lack it. Astringent, it causes a puckering sensation in the mouth and is important for balancing fruit character in red wines. Not present in whites.
Tartaric acid: Common acid found in grapes.
Tartrates: Crystals that precipitate out of the wine over time or exposure to cold temperatures.
TCA: Abbreviation for trichloroanisole, the cause of cork taint.
Temperature: Kit wine fermentations are usually best accomplished at temperatures much higher than most people expect—up to 75°F (24°C). Consult your instructions for the right temperature for your kit.
Terroir: The sum of the influences on the character in the wine that come from where the vines grow, including soil, climate, angle of slope, the aspect of the slope, latitude, etc. There is no precise translation in English, but the Latinate term haecceity comes close.
Typicity: Term describing how well a wine represents the characteristics of its grape variety and growing area.
Ullage: Space between the wine and the top of a wine bottle. As wine ages ullage increases as the wine gradually evaporates and seeps through the cork. This process depends on the ambient temperature and humidity.
Varietal: Fancy word for a single grape variety.
Vertical/horizontal wine tasting: In vertical tasting, different vintages of the same wine are tasted, emphasizing differences between various vintages. In horizontal tasting different wines the same vintage are tasted, exposing similarities of wines made that year.
Vinegar: Sour, acidic liquid derived from the oxidation of alcohol in wine.
Wine: Alcoholic beverage fermented from grape juice.
Wine Thief: Thin tube (designed to fit down the neck of a carboy) with narrowed openings at top and bottom. Used to remove samples from the carboy in order to take measurements.
Wine tasting: Sensory evaluation of wine, including taste, mouthfeel, aroma, and color.
Yeast: Single-celled fungal organism responsible for converting useless grape juice into delicious wine. Wine yeast strains are available in dehydrated dry form or in active liquid cultures.
Yeast Energizer: Similar to Yeast Nutrient but a slightly different blend of ingredients. It is suitable to restart stuck fermentations or boost the fermentation of very high gravity wines or meads. Consequently, Energizer can be added later in the fermentation process where Nutrient may not be desired.
Yeast Nutrient: A blend of ingredients that provide nitrogen, vitamins, and minerals required by the yeast during fermentation. Best added toward the beginning of fermentation so it is fully consumed by the yeast.