Homebrewing Glossary

Click any letter to jump to that part of the page.

A | B | C | D | E | F | G | H | I | J | K | L | M 

 N | O | P | Q | R | S | T | U | V | W | X | Y | Z

A

ABV: Alcohol by Volume. 

Acetic: A term for the odor or flavor of vinegar (Acetic Acid). Considered a flaw in wine and beer.

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.

Amylase Enzymes: The enzymes present in malted grains that are responsible for converting starches into sugars. There are two types - beta and alpha.

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.

B

Base Malt: Malt such as pale malt that serves as the "backbone" of the beer, as well as the main sugar source for fermentation.

Batch Sparge: Emptying the mash tun contents into the boil kettle and then refilling the mash tun with the hot liquor, recirculating and then draining the contents into the boil kettle to achieve the pre-boil volume.

Bittering Hops: Beer hops used early in the boil to impart bitterness. They do not generally impart much flavor or aroma.

Blind Tasting: Tasting and evaluating beer without knowing what it is. A very useful practice for winemakers, as it removes prejudices and expectations from the tasting environment.

Bottle Age: Time that beer has been allowed to mature in bottle.

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.

C

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. 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.

Cereal Mash: Used to gelatinize starches in unmalted grains in order for the conversion enzymes to gain access to them.

Cleaning: The physical action of removing dirt, visible residue or debris from equipment. Distinct from sanitizing, cleaning comes first.

Cold Break: Materials that precipitate out of the wort when it is chilled, consisting primarily of proteins and tannins. One of the components of trub. Some experts claim that carrying at least some of the cold break over into the fermenter is beneficial, because it acts as a yeast nutrient.

D

Decoction Mashing: All-grain brewing method where a portion of the grist is taken from the mash tun, boiled and then returned to the mash tun to achieve the next temperature rest.

Denature: The (optional) step of raising the mash temperature will cause the enzymes to inactivate, or denature, in the mash ceasing all enzymatic activity.

Dextrins: Long chain sugars produced by alpha amylase that are unfermentable by most yeast strains.

DMS (Dimethyl Sulfide): An off-flavor is excessive amounts that resembles the aroma or flavor of canned corn/cooked vegetables.

Doughing In: Mixing your milled grist with the hot strike water.

E

Endosperm: The white, starchy interior of the malted grain kernel.

Esters: The "fruity" flavor or aroma most commonly found in ales. Created from the interaction between acids and alcohol.

Ethanol (Ethyl Alcohol): The alcohol in alcoholic beverages. A byproduct of yeast metabolism produced during fermentation.

F

False Bottom: The piece in the bottom of the mash tun responsible for separating the grain from the liquid portion of the mash.

Fermentation: Conversion of sugar to alcohol and carbon dioxide by yeast.

Finish: The very last taste impression of wine or beer. Flavor, texture, and duration are all considered when evaluating the finish.

G

H

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.

Hop Jack: Another term for a hop strainer.

Horizontal Tasting: Tasting different beers of the same vintage, exposing similarities of beers made that year.

Hot Break: Material which precipitates out of the wort during the boil, consisting primarily of proteins and tannins. One of the components of trub. Hot break is generally removed prior to fermentation.

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.

Hot Break: Material which precipitates out of the wort during the boil, consisting primarily of proteins and tannins. One of the components of trub. Hot break is generally removed prior to fermentation.

Hot Liquor Tank: A vessel for storing hot water.

I

Irish Moss: Is a form of dried seaweed, used to help clarify beer. Irish moss is added to the kettle during the boil; it causes more of the dissolved proteins to precipitate out, in the form of hot break. This means there are less proteins left in the finished beer, resulting in less chill haze.

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.

J

K

Krausen: Pronounced, kroy-zen, is the foamy and bubbly head that forms on top of beer during primary fermentation. As yeast ferments the sugars in a beer, it creates a great deal of CO2. The Krausen is formed as the CO2 rises to the top of the beer mixing with proteins, yeast and residues in the beer forming a tall layer of yeast saturated bubbles.

L

Lautering: The process of separating the spent grains from the mash liquid. The false bottom is responsible for this separation.

Lees: Sediment of dead and dormant yeast on the bottom of a fermenting vessel or barrel.

Liquor: The term for brewing water.

Litre: Standard unit of volume in Canada. 33.8 fluid ounces, or just over a quart.

M

Malted Grains: Malting is the process in which raw grain kernels are allowed to germinate under certain conditions and are then dried in a kiln. This process ensures that the enzymes are present and the starchy internals of the grain are suitable for mashing.

Mashing: The “mash” is the term used to describe the combination of malted grains and hot water. At the most basic level, this is where the enzymes convert the starch into fermentable sugars.

Mash Tun: The physical vessel where the mash is conducted.

Milled: Crushing, or breaking up the grain kernels into smaller pieces. Each grain kernel should be broken up into roughly 5 to 6 pieces before mashing.

Multi-Step Mashing: Mash method that incorporates several temperature rests through direct heat or the addition of boiling water (in a single-infusion system).

N

Nose: A beer’s smell, often referred to as aroma or bouquet.

O

Organoleptic: The sensory properties of foods or chemical components as sensed by taste, color, odor and feel.

Oxidation: Degradation of beer through exposure to oxygen.

P

Pre-Boil Volume: The amount of wort collected before the boil has begun. This will be greater than the total batch volume of the recipe.

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.

Protein Rest: A protein rest is done before a saccharification rest (resting your mash in the 148-158 °F range for ~60-90 minutes) by bringing your mash to 122-131 °F for ~20 minutes. Most malts do not require the use of a protein rest, as they have been well modified (a high degree of of breakdown during malting of the protein-starch matrix in the malted grain).

Q

Quaffing:  A lot like drinking, but with more spilling and loud voices. Used to describe simple, everyday beers intended for casual consumption

R

Racking: Transferring beer 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 beer, and may also be used to introduce small amounts of oxygen to the beer to assist in flavor development.

Refractometer: A device that  instantly reads the specific gravity (in Brix) of unfermented wort 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 beer.

Runnings: The wort that flows out of the mash tun after the mash is complete.

Russian Imperial Stout: A very strong, dark (nearly black), intensely roasty and malty ale. So named because it supposedly was originally brewed (in England) for export to Russia.

S

Saccharification: The enzymatic process of converting starches to sugars to create wort.

Saccharomyces Carlsbergensis: Scientific name for lager yeast. Bottom fermenting yeast.

Saccharomyces Cerevisiae: Scientific name for ale yeast. Top fermenting yeast.

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 beer clears and stabilizes prior to bottling or kegging. Once fermentation has subsided, the beer 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 beer 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.

Silica Gel: A hard, glassy substance made from specially processed silica (sand), which contains microscopic pores. Sometimes used as a wine or beer clarification agent; can also be used as a dessicant (moisture absorber), due to its extreme attraction for water.

Single Infusion: Mashing at a single temperature for the entirety of the mash duration.

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.

Slurry: A thin mixture of water and insoluble solids.

Sparge: The act of rinsing the grains from the completed mash with the hot water contained in the hot liquor tank.

Specialty Malts: Malts used in lesser quantities in the mash that are usually used to impart flavor/color/aroma. Most specialty grains do not need to be mashed and can be steeped.

Specific Gravity (S.G.): Measurement of the density of wort or beer in relation to water. Used for tracking the progress of fermentation (as sugar is replaced by alcohol, beer becomes less dense and the hydrometer sinks deeper into the liquid and gives a lower reading). Potential alcohol can be calculated from the starting s.g.

Spent Grain: What the grist is called once the mash is complete and the available starches have been converted into sugars.

Specific Gravity (S.G.): Measurement of the density of wort 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.

Spigot: A faucet used to regulate the flow of liquids from the bunghole of a barrel.

Spiles: Small, wooden pegs or plugs, used to close vent holes in barrels.

Starch: Complex branches chain of from 25 to more than 1000 glucose residues. Starch is often used as a general term for all large glucose sugars (amylose, amylopectin, and true starch). This usage is, in strict biochemical terms, incorrect.

Starch Haze: A haze in the finished beer which results from the presence of unconverted starch. Starch haze differs from chill haze in that it is present regardless of whether the beer is chilled, or at room temperature.

Starter: A vigorous yeast culture prepared in advance to ensure a strong initial ferment. Also describes reserving and nurturing a sample of yeast for future use.

Steam Beer: Top fermenting beer of very high carbon dioxide content, originated in California. Aka California Common.

Steeping Grains: Steeping is like making tea- you’re extracting flavor from grains and sugar/flavor/color release into water. Steeping contributes much more color and flavor to a beer than sugars. Used in extract brewing applications. It is the process of soaking grains (usually specialty grains) in water to extract color/flavor/aroma/body. Steeping differs from mashing in that there is no starch-to-sugar conversion.

Sterilize: To kill all microbes present in a substance (or on surface). Typically requires the use of an autoclave.

Stewing: The process by which crystal malts are produced. Whole damp malt is heated to saccharification temperatures, allowing the amylase enzymes which are naturally present in the malt to convert the starches into sugars. The malt is then kilned (heated), to dry it and impart color and flavor.

Strike Water: Strike water is the brewing name for the water with which the milled grist is mixed to create the mash.

Stuck: Fermentation that stops prematurely. There are a variety of possible causes including excessively high fermentation temperatures, nutrient deficiency or excessively high sugar contents.

Sucrose: This disaccharide consists of a fructose molecule joined with a glucose molecule. It is most readily available as cane sugar.

Suspension: The state of a solid when its particles are mixed with, but undissolved in, a fluid or another solid; a two-phase system consisting of a finely divided solid dispersed in a solid, liquid or gas.

Sweet Stout: A sub-style of Stout characterized by a sweet taste. The sweetness is usually achieved by the addition of lactose (a.k.a. milk sugar), which is not fermentable by brewers yeast. Because of the use of lactose, it is also sometimes referred to as Milk Stout.

T

Temperature Rest: In all-grain brewing, refers to bringing the mash to a specific temperature, and holding that temperature for a specified period of time.

Titration: A method, or the process, of using a standard solution to determine the strength of another solution.

Torrified: Puffed. Many grains are available in torrified form, alas, all must be mashed.

Trappist Ale: In its broadest sense, refers to any style of ale that is brewed in a Trappist monastery. The most commonly seen sub-styles of Trappist Ale are Dubbel and Tripel; other beers which do not fit either of these styles may still be referred to as Trappist Ales, provided that they are still brewed at a Trappist monastery. All authentic Trappist Ales are currently produced in Belgium or Holland.

Treacle: The British term for molasses.

Tripel: A pale, very strong Belgian ale. high alcohol content is achieved without making the beer too sweet, but adding generous amounts of sucrose (cane or beet sugar) to the wort. This can be done without the negative flavor impacts generally associated with the use of sucrose, because there is also a lot of malt present (remember, this is a high gravity style). One of the "Trappist" styles.

Trub: The whitish, scummy layer that forms on the bottom of fermenting wort containing precipitated proteins, dead or dying yeast cells, lipids and fats, and other molecules. If beer is not removed from contact with the trub after two to three weeks, off flavors can develop.

Turbid: Cloudy or opaque.

Turbinado Sugar: Cane sugar which has not been fully refined. Still contains some of the natural molasses, giving it a golden color, and a rum-like flavor. Sometimes called raw sugar.

U

Underdough: The sludge contained between the false bottom and the real bottom of a straining tank. It consists of rather hard parts of the mash and contains at times considerable amounts of starch.

Upperdough: The sludge on top of the layer of grains in a straining tank, consisting of finely divided light particles, mostly coagulated protein.

V

Vat: Usually a fermenting or storage vessel.

Vertical Tasting: A tasting of several different vintages of the exact same wine or beer.

Vienna Lager: An amber or light brown lager, with a light toasted character.

Victory Malt: Victory Malt is a toasted malt, similar to biscuit malt, that can improve body and head retention in beer. The color is between 25-28 Lovibond, and has been described as slightly red or amber in color with highlights of orange.

Viscosity: Stickiness, aka; the resistance offered by a fluid (liquid or gas) to flow. The viscosity is a characteristic property and is a measure of the combined effects of adhesion and cohesion.

Vorlauf: Recirculating the mash liquid to help set the grains on the false bottom. This will cause the mash liquid to clarify and help to remove any small grain particles from the runnings.

W

Weizen: A German-style wheat ale, with a fruity/spicy character imparted by unique yeast strains. Unfiltered versions are generally referred to as Hefeweizen.

Weizenbock: A Weizen (German-style wheat ale) which has been brewed to Bockstrength (OG of at least 1.066).

Wheat: The second most common grain used in beer brewing. Malted wheat makes up at least 50% of the grist of traditional Weizen and Hefeweizen beers, and may also be added in lesser amounts in other styles (generally as an aid to head retention). Unmalted wheat makes up a substantial percentage of the grist in Witbier and Lambic.

Whirlfloc: An enhanced blend of Irish Moss and purified carrageenan that aids in the coagulation and settling of haze-producing proteins and beta glucans.

Whirlpool: Round cylindrical flat bottom tank into which hot wort from the brew kettle is pumped at high velocity tangentially to its straight wall. This high speed stream causes the wort in the tank to rotate slowly and to deposit its trub in a more or less compact cone in the center of the tank.

Wild Yeast: Uninvited yeast other than cultured yeasts.

Witbier: A pale, cloudy beer, brewed with a high percentage of unmalted wheat (and sometimes oats), and spiced with coriander and orange peel.

Wort: Alcoholic beverage fermented from grape juice.

X

Y

Yeast: Single-celled fungal organism responsible for converting useless wort into delicious beer. Beer yeast strains are available in dehydrated dry form or in active liquid cultures.

Yeast Crop: Yeast collected from fermentors during or after the fermentation.

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 beers. 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.

Yield of: Number of pounds of extract, obtained from 100 pounds of brewing material, given in percent. Also kilos extract per kilo brewing material. Distinguish between laboratory yield of malt and adjunct which is determined by standard ASBC methods and brewhouse yield, which depends on equipment and operating conditions. Brewhouse yield ranges from 92 to 98% of laboratory yields.

Z

Zymase: A group of enzymes (originally found in yeasts and bacteria) which, in the presence of oxygen, convert glucose and a few other carbohydrates into carbon dioxide and water or, in the absence of oxygen, into alcohol and carbon dioxide or into lactic acid.

Zymurgy: The chemistry of fermentation with yeasts, especially the science involved in beer and wine making.