They key acid in vinegar. This acid can appear in homebrew batches easily if proper sanitation methods are not used. If a batch is seriously infected it can either be allowed to continue production and used as kitchen vinegar or the batch of homebrew must be destroyed.


A crystallized blend of acids commonly found in wines. Used by homebrewers to correct PH balance in batches that are too alkaline. The blend is often preferable to using any single brewing acid to promote an overall balance of flavors.


Acidity is the PH or acid level of wine. Most finished wines are naturally high in acid and this is often a hallmark flavor in most wines. A high acidity also helps preserve the wine over time. The opposite of acidity is alkalinity.


Fermentation in the presence of oxygen. The first few 20-40 days of fermentation is aerobic. The aerobic fermentation stage is often the most active (lots of bubbling and foaming) and usually takes place in a sealed bucket with several inches of airspace above the liquid. The majority of alcohol is produced in the the aerobic fermentation stage.


Any secondary source of starches or sugars such as rice, oatmeal, corn, corn syrup, other grains, etc. Used more in beer making than wine.


Any device that allows gas flow in only one direction. Most airlocks used in home brewing are small plastic devices partially filled with liquid. The design allows carbon dioxide gases produced during fermentation to exit the fermenting container without allowing contaminated air to re-enter.


Referenced in homebrewing as drinkable or Ethyl Alcohol or Ethanol, CH3CH2OH. Causes intoxication and has preservative properties. Produced by yeast as a byproduct of the fermentation process.


The percentage of a liquid (wine in this case) that is alcohol. This can be determined by comparing beginning sugar levels in a batch of homebrew with the ending sugar levels.


The lack of acid.


The more advanced form of beer brewing that involves malting grains. The alternative is using a malt extract which is faster and less involved method of brewing, but does not allow for as much control over the recipe as mashing and sparging your own grains. More advanced homebrewers often prefer milling and mashing their own grains instead of using extracts.


The second stage of fermentation that is conducted in an oxygen-deprived environment, usually in a glass carboy with a minimum of air space. Great care is taken during this stage of fermentation not to over-expose the wine to air by means of splashing or sloshing. This stage of fermentation is less responsible for the production of alcohol, but produces more of the characteristic flavors usually found in wine.


The smell of a wine, also called the “nose” of a wine or the bouquet. This is especially important in all food since the human sense of smell and taste are closely related.


Vitamin C. Usually found in a powdered crystalline form and used as a key component in acid blend. A moderate to large amount of ascorbic acid can help prevent your wine from getting a “rusty” or over-oxygenated flavor.


A component of flavor in a wine’s taste. This is often best described as the “dryness” of a wine or the flavor that makes you want to pucker your lips. This flavor is found abundantly in red wines especially and is caused by tannins in the wine (usually extracted from grape skins). White wines generally have far fewer tannins and thus do not taste as dry normally. They also help in aging a wine. Wines without high tannin levels generally do not age well. A highly astringent wine can be mellowed by allowing it to “breathe” after opening, thus oxygenating the wine.


The robustness of the yeast in their ability to convert sugars (in various forms) into alcohol. Various strains of yeast have different attenuation levels and are often suited more for brewing one type of beer over another. See also, Flocculation.



The traditional winemaker’s form of measuring alcohol potential of must (unfermented wine). It measures dissolved solids in the wine (almost entirely sugar) and can be used to predict approximate alcohol levels in a finished wine. Specific Gravity measurements are more accurate. Most modern hydrometers measure both Balling and Specific Gravity. Balling is also known as “Brix” or “Brix Level”.


Oak barrels are most commonly used in traditional wine making. The wood gives specific flavors to wines and also allows for controlled oxygenation and evaporation. The charring of a barrel also has an effect on flavor. Modern homebrewers can use oak chips or oak flavor extracts to achieve these flavor effects but are arguably a poor substitute for oak aging. Not all wines benefit from oak storage. Also used heavily in the production of whiskey or other distilled spirits for the same flavors as well as in some beers.


31 US gallons. Most kegs are ½ barrels.


The generic term used to refer to any given iteration of fermentation in the brewing industry.


A tube used to vent carbon dioxide from fermentation. If one end of the tube is submersed in water and the other end is sealed inside the fermentation vessel a blow-off tube ban be used as an airlock.


A flavor characteristic often described as the “mouth feel” or the overall taste and texture of a wine taking into account all of a wine’s components .


The odor or smell of a wine, usually used to describe a more complex blend of smells from an aged wine.


Wine distilled to produce a higher alcohol content.


See Balling.



Chalk. Used to leech acids from wine. This is generally no longer used because it can leave a cloudy residue.


A sterilizer used in home brewing. Each tablet contains a minor amount of potassium metabisulfite. It is often easier to measure and crush tablets than to get an accurate measuring of sterilizer. Too much sterilizer in your wine can destroy it’s flavor. Wait at least 24 hours after using campden tablets on your wine before adding yeast, otherwise the tablets may hinder your yeast as well.


The mass of pulp and fruit skins that accumulate at the top of a primary fermenter. This mass should be “punched down” or broken up several times daily to keep bacteria from growing in the mass and to further expose the wine to the vital flavor agents in the plant mass. The use of a fermentation bag (usually made of nylon) can help keep a mass from forming, but the bag should still be squeezed regularly to extract flavors from the fruit.


See Crystal Malt.


The gas given off by yeast as part of the fermentation process. Also protects wine and beer from over-oxydization during fermenting. Carbon dioxide dissolved in a liquid also produces the “fizz” found in beer and bottled sodas.


The process of dissolving carbon dioxide in a liquid such as beer, wine or soda.


A container usually made of glass or plastic with a narrow or tapered mouth designed to expose as little of the liquid stored inside to air as possible. Glass has several advantages over plastic such as ease of sterilization, not absorbing flavors or leeching petroleum used in the plastics into the wine as well as generally being easier to clean. The standard size is 5 gallons, but other sizes are also available. Commonly referred to as a “water jug” since they closely resemble the storage drums that office water dispensers use.


Acid commonly found in oranges and other citric fruits. A major component in acid blends used in brewing.


The processes of making an opaque liquid clear by removing suspended solids. This is often accomplished by the use of fining agents such as bentonite or sparkloid or by mechanical filtration. To clarify a wine is to make it “bright” or “brilliant”.


To remove the water or other non-essential components from a liquid to make it more compact. (Think orange juice from concentrate). Malt Extract is concentrated wort (unfermented beer). Grape concentrates are also available for homebrewing wines. This is especially useful for making hard-to-find wine or for making wine from fruit that is out of season.


A derogatory term used for wine made from grapes or fruits that are not generally used in commercial winemakeing. Pear or Strawberry wine are referred to as country wines because traditional winemakers consider these fruits unsuitable for making wine because the sugar and acid levels often have to be manually adjusted prior to fermentation. Anyone who has ever tasted good country wine will often prefer it to any store-bought wine.


The generic term for any brewing operation that is not conducted on a large industrial scale. This encompasses everything from making wine or beer in your kitchen to larger commercial operations that emphasize quality and flavor over mass-production. Your next door neighbor’s personal recipe beer is a craft brew and many consider operations such as Samual Adams beers to be a craft brew because it focuses more on flavor and quality than on cost.


A major type of brewing grain that does not require mashing. Used by extract and whole-grain brewers alike.



To pour a liquid from one vessel to another for the purposes of “breathing” or to serving from the other vessel.


A sweet wine usually served after dinner with deserts where it compliments the flavors best, sometimes fortified. Especially sweet wines are often called dessert wines. Usually has a marked lack of astringency.


A starch molecule created from starch during the mashing process that also contributes to the “body” of flavor of a beer. Also a type of crystal malt that adds especially high levels of dextrin to beer.


A somewhat complicated process of removing yeast sediment from a bottle without allowing the carbonation in the liquid to escape. This is especially useful in making champaign which is highly carbonated. In fact is is sometimes even called “champaigning” and is accomplished by freezing the necks of the bottles and removing the sediment settled in the neck (bottles frozen upside down so sediment settled there) and re-corking. Not normally practiced by homebrewers.


The process of condensing alcoholic beverages (usually by heat and condensation) to concentrate flavor and raise the overall alcohol content. Distilling without a commercial license in the US is illegal unless for fuel or agricultural purposes. A home-made distillation assembly is often called a “still” and is used to produce bootleg alcohol (aka moonshine). Distillation can produce toxic chemicals if not carefully controlled.


The opposite of sweet. Various yeast strains have different tollerances to the presence of alcohol. Some yeast will die off in in a liquid with a relatively low alcohol level while others will thrive in very high alcohol levels and convert virtually all sugars. Therefor, the yeast used has a large effect on the dryness of a finished wine or beer.


The process of adding hops purely for flavor effect either during or after fermentation. This process avoids extracting any of the bitter compounds found in hops but contributes much to the flavor and aroma. Commonly used in pale ale style beers.



Drinkable alcohol (CH3CH2OH), the byproduct of fermentation, also used recently as a “biofuel”.



A false bottom is simply a strainer used in the sparging process of beer production. This strainer can either be built directly into a brew pot or vessel or can simply be a mesh (usually nylon) bag used to separate grain from liquid in the sparging process. Think of it as a built-in strainer.


The process of yeast eating sugar and outputting drinkable alcohol and carbon dioxide as well as other secondary byproducts that usually form sediments. Fermentation is divided into two stages, Aerobic (with oxygen) and Anaerobic (without oxygen). The majority of alcohol is created in primary fermentation while most flavor characteristics are created in secondary fermentation.


See Airlock.

FERMENTER / Fermentor

The container in which fermentation takes place, usually a wide mouthed vessel for primary fermentation and a small mouthed vessel for secondary. Usually made of glass or plastic for homebrewing and stainless steel for commercial brewing


The process of removing solids from wine or beer. This can be done by mechanical filter (usually with a paper medium) or by use of fining agents such as bentonite, sparkloid or freezing. Great care should be taken with mechanical filtration methods as they can easily over-expose wine to air and thus oxygenate the wine and adversely affect the flavor. Mechanical filtration is not as popular in homebrewing but is industry standard in commercial winemaking.


Additives used specifically to clarify, filter or otherwise remove solids from a beer. Common fining agents are bentonite (an ionized clay) and sparkloid but eggshells, irish moss and even bull’s blood has been used to force particles to coagulate and settle to the bottom of a container.


Clumping together of particles so that they can settle to the bottom of a container by means of gravity (perciptation). Various strains of yeast have specific flocculation qualities. See also, Attenuation.


To boost or otherwise raise the overall alcohol content of a wine by means other than fermentation.



A measurement of the sugar in a liquid. Measurements are temperature sensitive and are usually calibrated for 70 degrees. 1.065 is 65 gravity points. Used to calculate the initial sugar in a batch and compare to the finishing gravity after fermentation to determine alcohol content. More accurate than Brix scale.



A small green bud that provides the flavor, aroma and bitterness to all beer. Often added to beers in various stages of boiling or after boiling (known as dry-hopping). Also a key natural preservative in beers. The quality of hops have a direct effect on the quality of finished beer.


A device used to measure the gravity or bix of a liquid to determine sugar content and thereby evaluate alcohol content. Commonly a weighted glass tube with measurement lines that is suspended in liquid. The reading is taken at the point where the glass tube protrudes from the liquid. Temperate compensations must be made for readings. Most homebrewing hydrometers are “triple scale” which displays brix (or balling), gravity and overall potential alcohol.



The grimey foam produced during beer fermentation that is often removed for flavoring reasons. Also referred to as a method of fermenting in a finished bottle in order to achieve carbonation by means of saving some of the original un-fermented solution and adding back to the beverage at the time of final bottling. A more complicated method of carbonation but often praised for better flavoring.



See Sparging and Lauter Tun.


Any container designed specifically to sparge wort through grains for the purposes of extracting additional sugars and flavors. Usually equipped with a false bottom to separate grains from liquids. Most often used for a vessel dedicated to this purpose but can also be any makeshift container or set of containers that serve this purpose.


Winemaker terminology for sediment that accumulates at the bottom of a fermentation vessel. Regular racking is required to separate wine from sediment since prolonged exposure can cause undesirable flavors.



One of the common acids in acid blend, mostly derived from apples.


Conversion of maltic acid to lactic acid, a much less noticeable acid. This reduces the overall acidity of the wine and adds key flavor characteristics. This is usually accomplished by adding specific bacteria cultures during fermentation.


This has several meanings in homebrewing. Malt is the extract composed mostly of sugar (concentrated wort) used when brewing beer from extract. This usually comes in either a syrup or powder form.

Malt is also the term used for the grains that whole-grain brewers use for non-extract brewing. The process of “malting” is the stage where grains are soaked and starches are converted to sugars. There are 3 major methods of malting that result in the 3 distinctly different varieties of malted grains used in brewing, Roasted, Caramel and Pale Ale.


A concentrated syrup packed with malt sugars used as a base for homebrewing beers. It is essentially concentrated wort. Extract brewing is the simple form of home beer brewing as opposed to All-grain brewing does not use a malt-extract since they mash the sugars and flavors directly from the grains manually in the mashing process.


The process of soaking malted grains in water at various temperatures to promote enzymes to convert starches to sugars. Temperature is critical in this process as the enzymes activate in specific temperature ranges. After several periods of soaking at the given ranges the water is drained off via a “false bottom” or a nylon bag. The same liquid may also be run-through the grains again in a process known as sparging in an effort to extract as much sugar and flavor as possible from the grains. The final product of mashing is a sweet liquid known as “wort” which is high in sugar and highly fermentable.


The container used to hold grains and liquids during the mashing process. Can be a simple kettle or a container with a false bottom to allow easy separation of liquid from solid.


A chemical in the sulfite family that is used both in industrial and home winemakeing. Potassium metabisulfite is the active ingredient in campden tablets and is often added directly to wine batches to sterilize them. Sodium Metabisulfite is commonly used as a sanitizer.


The wine maker’s equivalent to wort. This is the un-fermented mixture of fruit and flavor agents with sugars. Wine is often called “must” until after the fermentation process is complete.



The over-exposure of wine to oxygen. This is generally not an issue during aerobic fermentation when oxygen is needed for yeast development. Over-exposure of wine to air during secondary fermentation by means of allowing headspace in a carboy, allowing water to splash during racking or during a mechanical filtration process can all easily cause over-oxygenation. This will drastically effect the flavors of the wine giving a harsh, stale or sometimes “rusty” flavor. Wine should always be kept in a sealed container with a minimum of airspace.

Some harsher wines, especially astringent reds, benefit from mild or controlled oxygenation. This is accomplished either through aging in wooden barrels that allow controlled oxygenation when monitored or by opening a bottle and allowing it to “breath” for a few minutes before serving.

Acids in wine can help protect from over-oxygenation just as the acid from lemon juice will keep an apple from turning brown when exposed to air. The corrosive properties of oxygen interacting with metal also produces rust.


A key element in the air we breath, used and monitored very closely during the brewing process. It is essential in the first stage of brewing and is avoided at all costs during the second stage of brewing.


The intentional process of allowing or introducing oxygen into must or wort prior to or during the first stage of fermentation. Oxygen helps in the reproduction of yeast cells. Oxygenation can be accomplished by many means such as leaving the wine exposed to headspace in the primary fermenter, shaking vigorously, or directly injecting oxygen into a liquid by means of an airstone. Once fermentation switches to secondary the oxygen will have either been depleted or displaced by carbon dioxide produced by yeast.



A naturally occurring enzyme that will break down the cellular structure of fruit and allow more juice extraction from fruit. It is really only needed in fresh fruit wines. Wines from extract or in meads that do not use fresh fruit do not generally benefit from pectic enzymes.


A measurement of ionic charge. Lower numbers have high concentrations of negative charges and higher numbers have positive charges. This is closely related to acidity, but does not represent a total profile of the acidity of a batch. Proper pH plays a role in fermentation and how overall flavor plays out in any given batch of wine or beer. Testing kits and pH correctors are available.


See metabisulfite


A stabilizer added to wine to coat yeast cells and prevent replication. It will only work when there is not an active fermentation present. It cannot fully arrest a fermentation, but it can help to control it. Usually added just prior to bottling.


The scale on the hydrometer that measures dissolved solids (mostly sugars). It shows the theoretical alcohol content of a wine if fully fermented until all sugars are consumed. Compare before and after fermentation readings to get actual alcohol levels. Specific Gravity measurements are generally more accurate.


The first phase of fermentation (aerobic fermentation, in the presence of oxygen) marked by rapid escape of carbon dioxide and occasionally foaming. This usually takes place in an wide mouthed container (like a bucket) with a given amount of headspace to promote access to oxygen. 80-90% of the alcohol that will be produced during fermentation will be produced during primary fermentation.


Adding carefully controlled amounts of sugars to a finished beer just prior to bottling. This produces controlled fermentation in the bottle and creates carbonation in the wine or beer.



The process of syphoning wine from one container to another with the intent of leaving behind sediments (lees). This is usually accomplished by means of a “racking cane” which is a tube of stiff plastic that is placed in the container with sediment present in such a way as to siphon the liquid and leave the solids at the bottom behind.


Brewing grains that have been roasted in a kiln for extended periods to produce darker richer flavors usually found in porters or stout beers. Roasted malts do not require mashing and are commonly used by both extract and whole grain brewers alike.



see hydrometer


The second stage of fermentation where exposure to oxygen is carefully controlled. Most of the traditional flavor and body of wine is produced during secondary fermentation. The remaining sugars in the wine are also converted to alcohol.


The process of separating liquids in a mash from the solids (grains) and then soaking the liquids through again to flush any residual sugars or flavor agents that remain in the grains.


Wine with carbonation (fizz) such as champaign. Allowing in-bottle fermentation will produce sparkling wine. Take GREAT care to limit the amount of sugars available to yeast during in-bottle fermentation or the bottles may pop their corks from gas pressures or explode entirely.


see gravity


To kill or control all microbial activity (yeast and others) in a wine prior to bottling. This is crucial to producing a consistent wine and prevent in-bottle fermentation. This is usually accomplished by means of adding Potassium Sorbate or campden tablets. It is absolutely essential if the wine is to be re-sweetened prior to bottling.


The primary form of chemically stored sugar in grains, rice and starchy veritable such as potatoes and pastas. In brewing, starches are converted to sugars by enzymes during the mashing process. This is not necessary in wines since most fruits do not store sugar as starch, but store them as simple sugars instead.


Wine without carbonation or “fizz”


The bane of all winemakers. This is a fermentation that has halted prematurely. This can be caused by several factors from improper temperature, to lack of nutrients for yeast to function to acid levels. If you are unsure if your fermentation is suck or finished measure with a hydrometer. If no dissolved solids are present (sugars) then fermentation is finished. You are ready to stabilize and bottle or you can add more sugar to continue fermentation. If the hydrometer still registers the presence of sugar then it is stuck.

To un-stick a fermentation first check and regulate temperature. If that does not resume fermentation then add additional yeast nutrient and check of acidity and ph. If that does not resume fermentation light a candle in honor of Baccus, the god of wine, and pray daily over your wine.


Sulfer dioxide which acts as an anti-oxidator and preservative.


The term used for a gravity feed of liquid using a tube from one container to another, commonly called “racking” in the wine industry.



An acid found in grape skins and other fruit skins as well as in grain husks. Tannin produces the astringent flavor in wine that makes you want to pucker your lips. Found in high levels in red wines. Higher tanning levels improve the aging quality of wine. Beer brewing and white wines do not typically use tannins.


A naturally occurring acid in ripe grapes that may form crystalline sediment. Does not generally have an effect on flavor


Acid that will eventually free of of it’s positive H+ ions and allow for accurate measure of acidity.


The act of measuring of ion charge by adding a special base and observing color change. Measures total acid.


See Titratable Acid.



Acetic acid and other compounds that make common household vinegar. This is the bane of all winemaker and usually means that vinegar bacteria had hopelessly infected the wine batch. Make plans for what you’re going to do with five gallons of salad dressing.


Wine Grapes. Grapes specifically suited for winemaking. Noted for high sugar content and usually has thicker skin.


This term has several meanings today. When used as a verb it is the process of harvesting and processing wine grapes. It is also used to describe any especially good year’s wine batch. Among wine snobs it typically means aged wine from a very good year. Also generally means something that is older and should be cherished.



See Airlock.


The sweet mixture of unfermented sugars and flavors produced from malting and mashing grains to make beer. Usually pronounced as “wert” or “wort”. The corresponding winemaker’s term is “must”.



Single-celled microorganisms from the fungus family used to ferment beer and wine and in bread making. Various strains of yeast have different characteristics such as alcohol and temperature tolerance, flocculation rates and flavor notes. Excellent source of Vitamin B.


A blend of nutrients, minerals and other components that promote healthy and viperous yeast growth and fermentation in general. Especially needed in meads which are made from honey and do not necessarily contain yeast-friendly elements. Can be beneficial to almost any batch of beer or wine.



The science of fermentation