Acetic Acid:
One of the primary acids in wine.
winemaking terminology
Glossary of Winemaking Terms
Wine making is a complex process that involves a wide variety of technical terms, concepts and jargon. It’s very important you understand the meaning of these terms as they will help you succeed making wine.
You don’t need to remember the meaning of all these terms, you’ll become familiar as your experience grows. You do need to remember that this page is here and that it’s a reference library for you. I recommend adding this to your bookmarks, so you can find it easily.
Here are some common wine making terms and their meanings.
Glossary Of Wine Terminology
Acetobacter:
Acetobacter is a genus of acetic acid bacteria. Acetic acid bacteria are characterized by the ability to convert ethanol to acetic acid in the presence of oxygen. Vinegar typically contains from 5% to 18% acetic acid by volume.
Acidity:
The level of tartness in the wine. The quality of wine that gives it its crispiness and vitality. A proper balance of acidity must be struck with the other elements of a wine, or else the wine may be said to be too sharp (having disproportionately high levels of acidity), or too flat (having disproportionately low levels of acidity). The three main acids found in wine are tartaric acid, malic acid and lactic acid. The first two come from the grapes and the third from Malolactic fermentation which often occurs in the winemaking process.
Aging:
The process of allowing wine to mature and develop flavor and aroma over time.
Airlock:
A Fermentation Lock or Airlock is a device used in wine making that allows Carbon Dioxide released during Fermentation to escape the Fermenter, while not allowing Air to enter the Fermenter. This is essential to prevent Oxidation.
Alcohol by Volume:
Abbreviated ABV: The percentage of alcohol in the wine.
Antioxidant:
Chemicals that are used to prevent the fruit Must from oxidizing, for example Sulphur Dioxide.
Barrel Fermented:
A wine fermented in oak barrels instead of stainless steel, glass or plastic.
Bentonite:
A specific type of clay use to clarify wine.
Blending:
The mixing of two or more specific parcels of wine together by winemakers. This is done to produce a consistent finished wine that is ready for bottling.
Bottle Age:
The length of time a wine has been allowed to age and mature in a bottle.
Bottle Variation:
The degree to which bottled wine of the same style and vintage can vary.
Brettanomyces:
A wine spoilage yeast that produces taints in wine commonly described as “barnyard” or “band-aids”.
Brix:
A measurement of the percentage of sugar in the Must. This is most easily done utilizing an instrument called a Hydrometer which measures sugar content by density. 1 degree Brix (°Bx) = 1g of sucrose / 100g of solution. Prior to fermentation, the BRIX reading is generally in an optimum range of 22-25%. At dryness or the endpoint of fermentation, the BRIX reading is generally 0%.
Campden Tablets:
Campden tablets (Potassium or Sodium Metabisulfite) are a Sulphur based product that are used primarily to sterilize in wine, cider and beer making to kill bacteria and to inhibit the growth of most Wild Yeast. Go to our Essential Wine Making Supplies page to purchase this item.
Cap:
During fermentation, the production of CO2 gases in the Must pushes the fruit skins to the top of the Primary Fermenter. This dense material is called a Cap and floats on the liquid.
Carbon Dioxide:
During Fermentation, Yeast transforms sugar present in the juice into Ethanol (alcohol) and Carbon Dioxide emitted as a gas (as a by-product).
Carboy:
A glass or plastic container that looks like an office water-cooler bottle or a large jug. Carboys usually come in five-gallon volumes and are used for fermenting juice, carrying out secondary fermentations, and for long-term storage. A Carboy is used with a rubber bung and airlock for fermentation, or a tight fitting cap for maturation.
Cellaring:
To age wine for the purpose of improvement.
Citric Acid:
An acid that occurs naturally in citrus fruits. Used in wine making to add acid to the flavor. Go to our Essential Wine Making Supplies page to purchase this item.
Clarification:
The process of removing impurities and sediment from the wine, refer Racking. This process can involve Fining or Filtration of wine to remove suspended solids.
Cork Taint:
A type of wine fault describing undesirable aromas and flavors often attributed to mold growth on corks.
The Crush:
Describes the procedure that strips the berries from the grape clusters, partially breaks the berries and discards the vast majority of the unwanted. The fruit and juice are transferred to fermenters.
Cut:
Describes the blending of wines with different and distinct characteristics to create something new. An example is blending a high acidity wine into a wine that is dominated by the opposite characteristic, low acidity. It can also mean blending a red wine with a white wine to make a Rose.
Debourbage:
Refers to a process in which the Must of a white wine is allowed to settle before Racking off. This process reduces the need for Fining or Filtration.
Devatting:
The process of separating red Must from Pomace, which can happen before or after Fermentation.
Dryness:
Describes how sweet the wine is, a dry wine has very little sweetness. A wine is dry when all of the sugar has been metabolized by the Yeast. Note, in sparkling wines, dry means sweat.
Enology/Oenology:
The study of wine.
Esters:
Compounds formed in wine either during Fermentation or the wine’s aging that contribute to a wine’s aroma.
Extraction:
From your chosen fruit, this is the process of separating the Sugars, Esters, Acids and Tannins into a liquid which Yeast can transform into wine. Common methods of extraction are Pressing, Boiling and Steeping (soaking your fruit in water).
Fermentation:
The process that converts most of the sugar in the fruit into alcohol and carbon dioxide gas (CO2). It is generally a 7-8 day process from the crush to the endpoint of Primary Fermentation.
Fermentation Vessel:
Fermentation Vessels, also known as Fermenters or FVs are the tanks, barrels, carboys, or other vessels where juice is held as it ferments into wine. Fermentation Vessels have always been an essential part of the homemade wine scene.
Final Gravity:
Abbreviated FG: Refers to the Specific Gravity of a Must once fermentation is complete.
Flip-top Bottle:
A flip-top, swing-top, lightning toggle, or Quillfeldt stopper (after the inventor, Charles de Quillfeldt) is a type of bail closure frequently used for bottles containing carbonated beverages, such as beer, mineral water and wine. The mouth of the bottle is sealed by a stopper, usually made of porcelain or plastic, fitted with a rubber gasket and held in place by a permanently attached wire bail.
Funnel:
A conical wide mouthed and narrow stemmed pipe which is used for pouring wine from a Fermenter into a bottle or from a bottle into a Decanter.
Hydrometer:
For Fermentation purposes, the Hydrometer is a tool used to measure the Specific Gravity of a liquid. In winemaking, the Specific Gravity reading tells us the amount of dissolved sugar in a liquid and enables us to calculate the amount of Alcohol created by Fermentation.
The Lees:
During storage in the secondary fermenters particulate debris falls to the bottom of the fermenter by gravity. This sediment is a chalky substrate containing dead Yeast cells and fine organic particulates that periodically are removed from fermenters by Racking.
Maceration:
The process of soaking the fruit skins in the juice during fermentation to extract flavor, color, and tannins.
Malolactic Fermentation:
A secondary fermentation process that converts malic acid to lactic acid, giving the wine a buttery, creamy taste. Also known as Malo or MLF, it involves bacteria instead of yeast and it is most desirable for red wines adding a more smooth, round and complex result. It can be introduced at the late stages of primary fermentation or at the endpoint after pressing. It changes malic acid to lactic acid. This process converts any remaining sugar to alcohol and completion of MLF is reached in approximately 3-4 weeks.
Mash:
During wine vinification by maceration, a chemical reaction occurs, which is activated by ripe grapes and the yeast in their skins. After removing the stems, the grapes are squashed in a mill. The resulting mixture of fruit pulp, skins, seeds and juice is called the Mash.
The Must:
In the world of wine making, the word “Must” means the total contents of crushed fruit, juice, skins and residual stems that will undergo primary fermentation.
Oaking:
Storage of clarified wine in oak barrels or containers containing oak chips to impart oak flavors to the finished wine.
Oak Barrel:
A wooden barrel used to age wine. The oak imparts flavor and aroma to the wine.
Original Gravity:
Abbreviated OG: Refers to the Specific Gravity of a Must before fermentation is started.
Oxidation:
The combination of air with components of fresh juice or wine. Oxidation is desirable during primary fermentation, but it is not desirable subsequently as it causes browning and reduces wine quality.
Pectinase:
Pectinases are a group of enzymes that breaks down Pectin, a polysaccharide found in plant cell walls. Pectinase enzymes are commonly used in processes involving the degradation of plant materials, such as speeding up the extraction of juice from fruit. Go to our Essential Wine Making Supplies page to purchase this item.
pH:
A measure of the intensity of acidity in the juice or wine. More specifically it measures the concentration of hydrogen ions. pH is one of the most important variables to track and modify in winemaking.
Pitch Rate:
The amount of yeast used in the primary fermentation. Professional winemakers typically inoculate Must at 3-6 million cells per mL in their fermentations.
Pomace:
The skins, stalks, and pips (seeds) that remain after making wine. Also called “Marc”.
Powdered Brewery Wash:
Powdered Brewery Wash (PBW) is a patented alkali cleaner originally developed for Coors, now widely used in commercial breweries and by home wine makers.
Primary Fermentation:
The Primary Fermentation phase is where the Yeast cells focus on proliferation, fueled by Wine Nutrients, Oxygen, and Sugar in the Must.
Primary Fermenter:
A container that holds the fruit and juice obtained after crushing. It is used during the first fermentation (Primary Fermentation) process.
Punching Down:
A procedure done at least one time daily during Primary Fermentation. It is done to prevent Oxidation and drying of the Cap. A manual punch down tool or long handle spoon is used to break up the cap, rewet the skins, and to push the skins to the bottom of the fermenter.
Racking:
The process of drawing wine off the sediment, such as Lees, after Fermentation and moving it into another vessel. This clarifies the wine. Once the Fermenter is cleaned, the wine is pumped back in and re-sealed. At least 3 rackings are done over a 2-3 month period before the wine is satisfactorily clarified and ready for aging.
Remontage:
French term for the process of pulling out wine from underneath the cap of grape skins and then pumping it back over the cap in order to stimulate maceration.
Residual Sugar:
The amount of sugar remaining in the wine after fermentation.
Sanitize:
Sanitization is the cleaning and disinfection of an area or an item. Sanitizing involves the use of heat or chemicals to reduce the number of microorganisms to safe levels.
Refer to our article How to Clean and Sanitize Winemaking Equipment for complete instructions.
Secondary Fermentation:
Secondary Fermentation is a process which entails a second period of Fermentation in a different vessel than the one used to start the Fermentation process. An example of this would be starting Fermentation in a Carboy then transferring the Must to a new Carboy leaving behind the Lees (sediment). Rather than being a separate, second Fermentation, this is most often one single Fermentation period that is conducted in multiple vessels.
Secondary Fermenter:
A closed-top fermenter that houses the pressed wine for a few months while malolactic fermentation and Clarification take place.
Sediment:
Sediment is just residual Yeast and other particles that fall to the bottom of the vessel after Fermentation and Aging.
Siphon:
A Siphon (also spelled Syphon) is any of a wide variety of devices that enable the flow of liquids through tubes from one vessel to another. In winemaking a Siphon is used to move clear wine to a new vessel leaving Sediment behind. This is part of the Clarification process.
Sodium Metabisulfite:
Sodium metabisulfite or sodium pyrosulfite (IUPAC spelling; Br. E. sodium metabisulphite or sodium pyrosulphite) is an inorganic compound of chemical formula Na2S2O5. The substance is sometimes referred to as disodium metabisulfite. It is used as a disinfectant, antioxidant, and preservative agent. When dissolved in water it forms sodium bisulfite. Go to our Essential Wine Making Supplies page to purchase this item.
Specific Gravity:
Abbreviated SG: Refers to the relative density compared to water. Specific Gravity of a liquid is measured by using a Hydrometer. The density of a Must is largely dependent on the sugar content of the liquid. During alcohol fermentation, yeast converts sugars into carbon dioxide and alcohol. By monitoring the decline in SG over time the brewer obtains information about the health and progress of the fermentation and determines that it is complete when gravity stops declining. If the fermentation is finished, the specific gravity is called the Final Gravity (abbreviated FG). For example, for a typical strength beer, Original Gravity (abbreviated OG) could be 1.050 and FG could be 1.010.
Straining Bag:
In winemaking, Straining Bags are used to remove fruit pulp, fruit skins and other solids from your Must, leaving behind the juice.
Sulfiting:
In winemaking, we use the preservative potassium meta-bisulfite to kill or discourage unwanted wild natural yeasts and to protect the Must and wine from harmful bacteria and mold spores. Without the addition of sulfites to wine, it would have a short lifespan and develop unpleasant taste characteristics. The small production winemaker has a decision making advantage to utilize the least amount of sulfites to accomplish adequate taste and protection requirements.
Swing-top Bottle:
A swing-top, flip-top, lightning toggle, or Quillfeldt stopper (after the inventor, Charles de Quillfeldt) is a type of bail closure frequently used for bottles containing carbonated beverages, such as beer, mineral water and wine. The mouth of the bottle is sealed by a stopper, usually made of porcelain or plastic, fitted with a rubber gasket and held in place by a permanently attached wire bail.
TA (Total Acidity):
TA is an abbreviation for the Total Acidity of the wine expressed as tartaric acid content. Wine grapes have three primary acids called tartaric, malic and citric. In wine making tartaric is by far more dominant and more important to measure its level (TA), and if necessary, make adjustments. TA adjustment is one of the more critical and subjective decisions of a winemaker that ultimately determines the flavor desirability of the finished product.
Tannin:
A bitter substance obtained primarily from grape stems and seeds. Tannins give wine a bitter, dry, or puckering feeling in the mouth while also acting as a preservative/anti-oxidant. Tannins add components to your wine that are desirable for wine complexity and structure. Go to our Essential Wine Making Supplies page to purchase this item.
Tartaric Acid:
Tartaric acid is a white, crystalline organic acid that occurs naturally in many fruits, most notably in grapes but also in tamarinds, bananas, avocados, and citrus. The acid itself is added to foods to impart its distinctive sour taste. Go to our Essential Wine Making Supplies page to purchase this item.
Terroir:
The environmental factors, such as soil, climate, and topography, that influence the character and flavor of the fruit used to make wine.
Topping Off:
Adding a similar wine to a vessel/barrel to bring the level back up. This is usually done when Racking and is due to evaporation that has reduced its volume.
Vintage:
The year in which the grapes were harvested.
Viticulture:
The science of growing grapes.
Wild Yeast:
Any of various yeasts occurring naturally in the air or on surfaces especially of fruits, as distinguished from those selected and artificially cultured.
Wine Nutrient Salts:
Usually a combination of Ammonium Phosphate, Potassium Phosphate and Magnesium Phosphate. These are added to the juice before Fermentation as many fruits lack the necessities Yeast needs to grow. Go to our Essential Wine Making Supplies page to purchase this item.
Yeast:
A microscopic unicellular fungi responsible for the conversion of sugars in Must to alcohol. Yeast changes your fruit juice to wine. In modern wine making, special yeast strains are used specifically to give your wine the qualities you desire.
Yeast Starter:
In winemaking, a Yeast Starter is a term referring to the method of cultivating additional Yeast cells from a yeast culture (usually dry yeast). Typically, this involves using Sanitized water and sugar in a Sanitized vessel, allowing the Yeast to proliferate before introducing it to the Fermentation process.
Refer to our article How To Make A Yeast Starter for complete instructions.
Final Words: Winemaking Terms
Wine making is a fascinating process that involves various techniques and terminology. By understanding these terms, you can gain a deeper appreciation for the art and science of wine making. Don’t be put off by these sometimes strange terms, use our Glossary as a reference to support you whenever needed.