Glossary of Home Brewing Terms

°B Degree Balling Grams of extract in 100 gm. water solution at 20°C., or pounds extract in 100 pounds of solution. Usually measured by determining specific gravity of the solution with a hydrometer (brewers use hydrometers which read directly in °B by referring to tables).

°Balling, °Brix, or °Plato – These three nearly identical units are the standard for the professional brewing industry for describing the amount of available extract as a weight percentage of cane sugar in solution, as opposed to specific gravity. Eg. 10 °Plato is equivalent to a specific gravity of 1.040.

18th Amendment – The 18th amendment of the United States Constitution effectively established the prohibition of alcoholic beverages in the United States by declaring illegal the production, transport and sale of alcohol (though not the consumption or private possession).

21st Amendment – The 21st amendment to the United States Constitution repealed the 18th Amendment to the United States Constitution, which had mandated nationwide Prohibition on alcohol on January 17, 1920.

Absorption: is the process by which a liquid or solid becomes absorbed by another liquid or solid, the particles that are absorbed being molecular or microscopic in size. A few solid bodies are capable of absorbing gases, for instance charcoal or activated carbon.

Acetaldehyde: A chemical and byproduct of fermentation that smells and tastes like green apples.

Acid: An acid is a hydrogen-containing substance that will dissociate in water to form hydrogen ions (H+).

Acid Rest: It is a step in the brewing process that is used to lower the pH of a mash early, around 95F.

Acrospire: The shoot of the barley grain, when it is germinated.

Adjunct: A fermentable ingredient used in brewing processes. Adjuncts are typically either rice or corn, but may also include honey, syrup, and numerous other sources of fermentable carbohydrates. They are commonly found in mass produced beer styled after American lager.

Aerate: to add air to the solution for the yeast to consume.

Aerobic: Bacteria and other forms of life that require oxygen in order to live.

Agar-Agar: a carbohydrate derived from the red seaweed Gelidium, forms gels with as little as a part per million of water. It is used to prepare bacteriological media.

Airlock: (or fermentation lock) A one-way valve that allows for the escape of carbon dioxide while preventing the entry of contaminants.

Alcohol: Any organic compound consisting of at least one hydroxyl group (OH).Beer contains alcohol between 3.0% and 14% ABV, usually around 5.9%. Most craft beer styles are around this amount.

Alcohol by Volume (ABV): Alcohol concentration is expressed as a percentage volume of alcohol per volume in a solution. 

Alcohol by Weight: To approximate the volumetric alcohol content, divide the original gravity by the final gravity, then by 0.0075.

Aldehyde: An alcohol precursor. Aldehydes can be formed from alcohol in some cases, creating unpleasant off flavors.

Ales: malt drinks fermented with yeasts that rise to the top of the vessel and form a yeast head at the end of fermentation.

Aleurone Layer – A living sheath covering the endosperm of barley corn that contains  enzymes.

Alkalinity – is determined by the number of equivalents of an acid that a base can react with in order to form a salt.

All Extract Beer –  Beer made from malt extract as opposed to one made from barley malt or through a combination of both.

All-grain beer –  Beer that is brewed exclusively from malted grains rather than malt extracts.

Alpha Acid – In hops, this is one of two primary soft resins (the other is beta acid). During wort boiling, alpha acids are converted to iso-alpha acids, which account for most of the bitterness in beer.

Alpha Acid Units (AAU) – A homebrewing measurement of hops. Equal to the weight in ounces multiplied by the percent of alpha acids.

Amino acids – Building blocks of proteins. There are twenty common amino acids: alanine, arginine, asparagine, aspartic acid, cysteine, glutamic acid, glutamine, glycine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine, threonine, tryptophan, tyrosine, and valine.

Ammonia – An extremely pungent, colorless, gaseous compound of nitrogen and hydrogen (NH3).

Amylase – A group of enzymes that convert starches into sugars, primarily alpha and beta  amylase. Also  known as diastatic enzymes.

amylase: An enzyme that breaks the bonds that bind starch molecules together.

Anaerobic – a process that does not require oxygen or may require the absence of it. Apparent Attenuation – measures how much fermentation the wort has undergone in  the process of becoming beerThe method is convenient for determining the degree of fermentation of beer with known original gravity.

Astringency – It is a characteristic of beer taste that is mostly caused by tannins, oxidized (phenols), and various aldehydes in stale beer.

Attenuation – The amount of sugar converted to alcohol and carbon dioxide.

Autolysis – Yeast die by running out of nutrients, causing off-flavors.

Bacteria – A one-celled organism that reproduces rapidly under strict temperature, pH, and other conditions.

Bacterium – An organism with a very simple cell structure that is part of a large group of microscopic organisms. They can manufacture their own food, live as parasites on other organisms, or feed on decaying matter.

Barley –  a grain that is used to make beer and certain distilled spirits as well as a food source for humans and animals.

Barm – the liquid part of the yeast that appears as froth on fermenting beer.

Barrel –  Common name for casks or kegs used to transport draft beer.

Beer – Any beverage made from fermented wort of malted barley flavored with hops.

Beer Stone – a deposit of calcium oxalate and organic matter on the surface of equipment exposed to beer for an extended period.

Bittering Hops – Refers to the addition of hops during the boiling stage of the brewing process. These hops are included in the start of the mash, providing beer with its characteristic bitterness.

Bitterness Unit(BU) – A way to measure the amount of bitterness in beer. Bitter substances are extracted from acidified beer with iso-octane and measured using a spectrophotometer at 275nm. BU is the same as International Bitterness Units (IBU).

BJCP Beer Judge Certification Program (BJCP) – Non-profit organization formed in 1985 to promote beer literacy, to appreciate real  beer, and to recognize beer tasting and evaluation skills.

Blow-off – An airlock arrangement consisting of a tube extending from the fermenter, submerged in a bucket of water, that allows carbon dioxide to escape and excess fermentation material to be removed.

Body (or mouthfeel) – In the mouth, beer has a consistency, thickness, and feeling of fullness.

Boiling – In the brewing process, wort (unfermented beer) is boiled inside a brew kettle.

Bomber – 22-ounce bottle of beer.

Bottle Conditioning – Natural carbonation of beer in a bottle occurs when additional wort or sugar is added during packaging and ferments.

Bottling – the process of putting the fermented beer into bottles.

Break – During the boiling stage (hot break) and cooling stage (cold break), protein matter clumps and separates.

Brettanomyces – An acidic yeast used in types of beer such as Lambic, Oud Bruin, and many barrel-aged styles.

Brew Kettle – A vessel used in brewing to boil unfermented beer (wort).

Brewpub – Restaurants and breweries that sell 25 percent or more of their beer on-site. The beer is often served directly from storage tanks of the brewery in bars and restaurants. When permitted by law, brewpubs sell beer “to-go” and/or distribute to off-site accounts.

British Thermal Unit (BTU)  – Measures the amount of heat required to raise the temperature of one pound of water by one degree Fahrenheit.

Budding – the process of producing new yeast cells from mother cells.

Buffer – Dissociates or reassociates with other chemical species to stabilize a solution’s pH.

Bung – Sealing stopper, usually a cylindrical piece of wood or plastic, fitted into the mouth of a cask or an older keg such as a Hoff-Stevens or Golden Gate.

Bung Holes – are the round holes in the sides of casks or older style kegs that are used to fill them with beer and then seal them.

Bunging –  refers to closing a container with a bung or connecting it to a pressure-regulating system; maintaining a certain amount of CO2.

Burton Snatch –  Sulphur odors indicate the presence of sulphate ions.

Buttery –  tasting like butter or butterscotch, owing to the presence of diacetyl.

Calcium Carbonate (CaCO3) –  is a mineral common in water of different origins. Sometimes added to beer to increase calcium and carbonate content.

Calcium Sulfate (CaSO4) – Mineral found in water of different origins. Also known as gypsum, this is sometimes added to beer during brewing to increase calcium content and sulfate content.

Calorie – The amount of heat required to raise the temperature of one gram of water by one degree Celsius.

Caramel Malt: A special malt made by gently heating it in a moist environment to produce sweet flavors and colors in beer. It’s also known as crystal malt.

Carbohydrate: A type of compound made up of carbon, hydrogen, and oxygen, found in sugars, starches, and other substances that provide food for yeast and bacteria.

Carbon Dioxide: A colorless gas produced by yeast during fermentation. It gives beer its fizziness and bubbles.

Carbonation: The process of adding carbon dioxide to a liquid, like beer, to make it bubbly and give it a refreshing texture.

Carboy: A large glass or plastic bottle used for fermenting and aging beer.

Carrageenan: A substance derived from Irish Moss that dissolves in hot water and is used for clarifying beer.

Caryophyllene: An essential oil found in hops, a plant used to add flavor and aroma to beer.

Cask: Originally an oak barrel for holding and dispensing beer, but now often made from stainless steel or aluminum. It comes in various sizes.

Cask Conditioning: Storing unpasteurized, unfiltered beer in cool cellars to allow it to mature and carbonate naturally.

Catalyst: A substance that speeds up a chemical reaction without being changed itself.

Cellaring: The process of storing and aging beer at a controlled temperature to enhance its flavors.

Cellulose: A component similar to starch but not broken down by starch enzymes. It affects the texture of beer.

Cenosillicaphobia: The fear of an empty beer glass.

Chalk: A term used for calcium carbonate, which is added to darken beers.

Check: When the main fermentation slows down or stops before the beer is fully fermented.

Chill Haze: A cloudy appearance in beer caused by proteins and tannins that become visible when the beer is cooled.

Chillproofing: A process to make beer resistant to chill haze by cooling it near freezing and adding specific substances during fermentation.

Chit Malt: A type of malt that is grown for a short period to give unique flavors to beer.

Clarification: The process of removing suspended particles from beer through mechanical or chemical means.

Closed Fermentation: Fermenting beer in a closed vessel to reduce the risk of contamination and oxidation.

CO2: The gas used to dispense beer from a keg.

Coagulation: The thickening or solidifying of a liquid, often caused by chemical reactions.

Cold Break: The proteins and tannins that clump together and settle during rapid cooling of the wort.

Colloid: A mixture where particles are suspended between a true solution and a visible solid.

Color: The shade or hue of a beer, which can be influenced by the grains and other ingredients used. It doesn’t determine alcohol level or calories.

Conditioning: The process of maturing and aging beer after the initial fermentation to refine its flavors and prevent unwanted compounds from forming.

Contract Brewing Company: A business that hires another brewery to produce its beer while handling marketing, sales, and distribution.

Coolship: A shallow tank used for cooling and clarifying hot wort.

Corn Sugar: A type of sugar used for carbonating beer during the bottling process.

Couch: Barley in the early stage of sprouting, often followed by a secondary steep.

Craft Brewery: A small and independent brewery according to the Brewers Association.

Culture: The cultivation of living organisms in a prepared medium, often referring to yeast in brewing.

Culture Medium: A nutrient system used for growing bacteria or cells in laboratory settings.

Cytase: An enzyme that dissolves the cellulose surrounding starch granules.

Decoction: A mashing method that involves boiling a portion of the mash and returning it to the main kettle.

Degrees Plato: A hydrometer scale used to measure the density of beer wort.

Dextrin: A soluble carbohydrate formed from starch during heating or enzymatic reactions.

Dextrose: A type of sugar that is similar to glucose but has a different molecular structure.

Diacetyl: A compound produced by yeast that can give beer a buttery or butterscotch flavor.

Diastase: An enzyme mixture that converts starch into sugars and dextrins.

Diastatic Power: The measurement of a malt’s ability to convert starches into sugars during mashing.

Diffusion: The movement of molecules from one substance to another, often through a membrane.

Dimethyl Sulfide (DMS): A flavor compound that can give beer a cooked vegetable taste at high concentrations.

Disaccharide: A sugar formed by combining two monosaccharide molecules.

Disinfecting: The process of eliminating disease-causing germs or insects.

Dispersion: The mixture of one substance into another, often referring to colloidal suspensions.

Dissociation: The separation of a compound into simpler molecules or ions.

Distillation: The process of separating liquids based on their boiling points and collecting the condensed vapors.

Doubling: Adding unfermented wort to beer during the main fermentation stage.

Doughing In: Mixing ground malt with water in the initial step of all-grain brewing.

Draft: Beer drawn from kegs or casks instead of being bottled.

Draught Beer: Beer served directly from kegs, casks, or serving tanks, typically fresher than packaged beer.

Dried Malt Extract (DME): Malt extract in powdered form, used in brewing and should be stored in a sealed, cool, and dry environment.

Dry Hopping: Adding hops to beer during fermentation or afterward to enhance its aroma without increasing bitterness.

Dry Kit: A homebrewing kit that includes dry malt extract, hops, and sometimes specialty malts.

Dual Purpose Hops: Hops used for both bittering and adding aroma to beer.

Effervescence: The bubbly sensation in beer caused by the presence of dissolved carbon dioxide gas.

Empirical: Based on practical experience or observation.

Emulsion: A mixture of two liquids, where one is dispersed in the other in the form of small droplets.

Endonuclease: An enzyme that breaks down nucleic acids at specific interior sites, producing fragments of various lengths.

Endosperm: The nutritious tissue of a seed that contains carbohydrates, proteins, and lipids.

Enzyme: A catalyst produced by living cells, including yeast, that helps facilitate chemical reactions in brewing.

Ester: A compound formed by the reaction of an acid with an alcohol, often providing fruity or floral aromas in beer.

Ethanol: The type of alcohol produced by yeast during fermentation.

Evaporation: The process of liquid turning into vapor and escaping from a substance.

Exonuclease: An enzyme that breaks down nucleic acids at the ends of polynucleotide chains.

Export: Beer produced specifically for the purpose of being exported to other countries.

Extract: The solids obtained from a liquid, such as wort, during brewing.

Farnesene: One of the essential oils found in hops that contributes to the aroma of beer.

Fatty Acid: A type of organic acid commonly found in fats, waxes, and essential oils.

Ferment: The chemical reaction process in which yeast converts sugars into alcohol and carbon dioxide.

Fermentation: The conversion of fermentable sugars into alcohol and carbon dioxide by yeast.

Filler: A machine used to pour liquid into bottles or containers.

Filter Mass: Prepared cotton or synthetic material used for filtering beer.

Filtration: The process of passing a liquid through a substance to remove suspended particles.

Final Gravity: The specific gravity of beer when fermentation is complete.

Fining: The addition of clarifying agents to beer to help remove suspended matter.

Finings: Materials, such as isinglass, used to clarify beer.

Finishing Hops: Hops added at the end of the brewing process to provide a pleasant flowery aroma.

Flavor Grains: Grains added to the mash to contribute flavor and color to beer.

Flocculation: The clumping together and settling of yeast cells out of solution during fermentation.

Flowery: Refers to the floral aroma found in some beers, often attributed to specific hop varieties.

Forced Carbonation: The process of rapidly adding carbon dioxide to beer under pressure.

Forcing: Speeding up a process, particularly the germination process.

Forcing Test: A method of estimating the shelf stability of packaged beer by subjecting it to elevated temperatures and measuring changes in haze.

Fore Masher: A device used to moisten crushed malt before it enters the mash tank.

Fresh Hopping: The addition of freshly harvested, undried hops during the brewing process.

Friability: The ease with which a substance can be crushed or pulverized.

Fructose: A type of sugar commonly found in fruits.

Full Mash: Refers to brewing beer using the traditional all-grain method.

Fungus: A type of organism that feeds on organic matter and includes mushrooms and molds.

Fusel Alcohol: Higher molecular weight alcohols that can contribute harsh flavors and are associated with hangovers.

Fusel Oil: A mixture of higher alcohols and their esters, often produced during fermentation.

Gallon: A unit of liquid volume measurement, with the U.S. gallon equal to 3.785 liters and the British gallon equal to 4.546 liters.

Gas: A state of matter in which the volume of a substance changes in direct proportion to its pressure and temperature. In the gaseous state, a given volume of any substance contains the same number of atoms or molecules.

Gas Volume: The volume of carbon dioxide in beer compared to the volume of beer liquid.

Gelatin: A colorless and tasteless protein often used as a fining agent in beer.

Gelatinization: The process of making starches soluble in water through heat or a combination of heat and enzyme action.

Gelatinize: To bring starch into a jelly-like consistency during mashing.

Germination: The beginning of vegetation or growth in seeds.

Gibberellic Acid: An additive used in malting to assist in water penetration into the grain.

Globulins: Proteins that are insoluble in water but soluble in dilute neutral solutions of salts of strong acids and strong bases.

Glucanase: An enzyme that acts on beta-glucans, a type of gum found in unmalted barley, oatmeal, and wheat.

Glucose: A simple sugar with the chemical formula C6H12O6, also known as dextrose.

Gluten: A viscid substance that gives adhesiveness to dough and is an insoluble protein.

Glycogen: A white, amorphous carbohydrate that is a constituent of yeast cells.

Grain Bag: A mesh bag used to hold grains during the sparging process.

Grainy: Tasting or smelling like cereal or raw grains.

Grant: A vessel placed between the straining tank and brew kettle to facilitate the straining of wort.

Gravity: A measurement of the concentration of malt sugar in the wort, often expressed as specific gravity.

Grist: Grain that has been or is to be ground.

Grits: Coarsely ground grain, often used to refer to coarse hominy.

Growler: A container, typically made of glass, used to carry draught beer purchased by volume from a tavern or brewpub. Often, customers pay a deposit on the container and can have it refilled with beer for future consumption.

Gruit: An herb mixture used for bittering and flavoring beer, popular before the extensive use of hops.

Gum: A colloidal substance exuded by or extracted from gum plants.

Gum Arabic: A mixture of several gums, including the best obtained from Acacia Senegal, that is completely soluble in water.

Gypsum: Calcium sulfate, often used to treat soft or neutral water to increase its hardness.

HBU (Home Bittering Unit): A measurement used to quantify the bitterness of homebrewed beer.

Head: The foam at the top of a poured beer.

Heat Exchanger: Equipment used to rapidly heat or cool the wort.

High Gravity: Refers to an original wort gravity of 1.060 or higher.

Homebrewing: The practice of making beer at home for personal consumption, legalized in the United States in 1979.

Hominy: A dry corn product made by breaking the kernels into particles larger than those typically referred to as “grits” in brewing.

Hop Jack: A hop strainer used in brewing.

Hop Nose: The fragrant aroma of hops in beer.

Hop Petals: The small leaves projecting from the spindle of the hop cone, consisting of bracts and bracteoles.

Hopback: A vessel filled with hops used to filter the finished wort and remove break material.

Hopping: The addition of hops to unfermented wort or fermented beer.

Hops: The flowers or cones of the hop plant used in brewing to provide bitterness, flavor, and aroma.

Hormone: A chemical messenger that regulates physiological activities in living organisms.

Hot Break: The coagulation and precipitation of proteins and tannins during wort boiling.

Hot Water Extract: An international unit for the total soluble extract of malt, measured as liter*degrees per kilogram.

Humidity: The amount of vapor present in the air, expressed either in its expansive force or as weight per given volume.

Humulene: One of the essential oils produced in the hop cones.

Husk: The dry outer layer of certain cereal seeds, often referring to the outer layer of malted barley.

Hydration: The process of solvation, particularly when water is the solvent.

Hydrolysis: The process of breaking down a chemical structure in water through chemical or biochemical means.

Hydrometer: A floating instrument used to determine the specific gravity of liquids, often used to measure the gravity of wort and beer.

Hydrometer: A glass instrument used to measure the specific gravity of liquids, including beer.

Hygroscopic: Having the property of readily absorbing and retaining moisture from the surrounding environment.

IBU (International Bitterness Unit): A unit of measurement used to express the bitterness of beer, typically measured in milligrams of iso-alpha-acids per liter of beer.

Immersion Chiller: A type of wort chiller, often made of copper, that is submerged in hot wort to rapidly cool it before fermentation.

Immersion Heater: A heating device used to maintain a constant temperature in the mash tun.

Independent: Refers to a craft brewery where less than 25 percent of the ownership or control is held by a non-craft brewery entity.

Indicator: A substance that undergoes a visible change, such as a color change, to indicate the presence or absence of certain substances in a solution.

Infection: The presence of undesired or foreign microorganisms in a culture medium or system, which can negatively impact the quality of the beer.

Infusion: In brewing, upward infusion refers to heating the mash stepwise without adding a portion of boiling mash, while infusion mash refers to a mashing method where heated water is added at specific temperatures to achieve target mashing temperatures.

Initial Mashing: The temperature at which malt and water are brought together at the beginning of the mashing process.

Injecting: The process of adding carbon dioxide to the finished beer to enhance carbonation.

Inoculate: The introduction of microorganisms, such as yeast or bacteria, into an environment that supports their growth, often done intentionally in brewing.

Inoculation: The introduction of minute organisms, such as yeast or bacteria, into a culture medium or system.

Invert Sugar: A mixture of dextrose and fructose, derived from the inversion of sucrose, often used in brewing to boost gravity or for priming.

Iodine: A non-metallic element used in various applications, including as an indicator in the iodine test for starch.

Iodine Test: A test used in brewing to check the conversion of starches to sugars. Iodine turns from yellow to dark blue, purple, or red in the presence of starch or dextrins but not sugars.

Iodophore: An iodine-based solution used for sterilizing equipment and surfaces in brewing.

Irish Moss: A dried red marine algae, often used as a clarifying agent in beer to help precipitate proteins during boiling.

Iron: An ion that can cause haze and oxidation in beer, as well as inhibit yeast activity.

Isinglass: A gelatinous substance derived from fish swim bladders, used as a fining agent in beer to help clarify and stabilize the finished product.

Iso-electric Point: The pH value at which the electrical charge of an amino acid is zero.

Isohumulones or Iso-alpha Acid: The isomerized form of alpha acids from hops, which contributes to the bitterness of beer.

Jingle: A beverage consisting of ale that is sweetened and flavored with nutmeg and apples.

Jockey Box: A beverage-dispensing system, often used for serving beer, that consists of a picnic cooler with an internal cooling coil and externally mounted taps.

Keg: A container, usually made of steel or aluminum, used for storing, transporting, and serving beer under pressure.

Kegging: The process of transferring beer from the fermenter to a keg.

Keggle: A nickname for a commercial beer keg that has been converted into a homebrewing beer kettle.

Kernel: The whole grain or seed of a cereal, or the inner portion of a seed.

Kettle: A large vessel used to heat the wort during brewing.

Kiln: A stove or furnace used for hardening, burning, or drying materials, such as grains or hops.

Kilning: The process of heat-drying malted barley in a kiln to stop germination and develop desired flavors, aromas, and colors.

Kraeusen: The rocky head of foam that forms on the surface of the wort during fermentation, or a method of conditioning beer by adding a small quantity of unfermented wort to create a secondary fermentation for natural carbonation.

Lace: The lacelike pattern of foam that sticks to the sides of a glass of beer after it has been partially or fully emptied.

Lactic Acid: An acid produced by bacteria during mashing or fermentation, which can contribute to sourness in beer.

Lactobacillus: A type of bacteria commonly associated with souring beer, though it can be intentionally introduced for certain styles.

Lactose: A non-fermentable sugar derived from milk, often used in brewing to add sweetness and body to beer, particularly in milk stouts.

Lag Phase: The period of adaptation and rapid aerobic growth of yeast after being pitched into the wort, typically lasting a few hours to a day.

Lager: A type of beer brewed with bottom-fermenting yeast at cooler temperatures, resulting in a clean and crisp character.

Lager Yeast: The specific strain of yeast, usually Saccharomyces pastorianus, used for fermenting lagers.

Lagering: The process of storing bottom-fermented beer at near-freezing temperatures for a period of time to allow the beer to mature and clarify.

Lambic: A traditional Belgian wheat beer that is spontaneously fermented using wild airborne yeast and bacteria.

Large Brewery: As defined by the Brewers Association, a brewery with an annual beer production of over 6,000,000 barrels.

Lauter: The process of separating the sweet wort from the spent grains during brewing.

Lauter Tun: A vessel with a false slotted bottom and a drain spigot used for separating the sweet wort from the spent grains.

Lautering: The process of separating the sweet wort from the spent grains in a lauter tun or other straining apparatus.

Leaching: The removal of soluble substances from a solid material, such as the extraction of fermentable sugars from grains during mashing.

Lightstruck (Skunked): A flavor and aroma defect that occurs when beer is exposed to ultraviolet or fluorescent light, resulting in a skunky odor and taste.

Lime: A caustic substance, often calcium oxide (CaO), used in various applications, including water treatment in brewing.

Lipase: An enzyme that catalyzes the hydrolysis of fats into fatty acids and glycerol.

Lipid: A class of organic compounds that includes fats, waxes, and related substances, important for cell structure and energy storage.

Liquefaction: The process of transforming a substance into a liquid state, often achieved through heating or dissolving.

Liquid Malt Extract: Malt extract in liquid form, often viscous and sticky, used as a source of fermentable sugars in brewing.

Liquid Yeast: A form of yeast preferred for its ease of use, typically provided in a liquid suspension.

Liquor: The water used in mashing and brewing, often treated or adjusted for specific brewing purposes.

Lovibond: A scale used to measure the color of grains and beer, indicating the intensity of the beer’s hue.

Lupulin: The yellow resinous powder found on the strobile (cone) of hops, containing essential oils and contributing to hop flavor and aroma.

Lupulin Glands: Small bright yellow nodes on the hop petals that contain the resins used by brewers.

Lupulones: The bitter resins found in the lupulin glands of hops, including co-lupulone, lupulone, and adlupul one.

Lysis: The breaking apart of cells, often referring to the rupture or destruction of yeast or bacterial cells.

Magnum Bottle: A 1.5L bottle commonly used for packaging beer.

Maillard Reaction: A browning reaction that occurs when sugars and amino acids react under high heat, resulting in the formation of complex flavor compounds and pigments.

Maize: Another term for Indian corn, often used as an adjunct in brewing.

Malt Extract: A concentrated syrup or dry powder made from malt, used as a source of fermentable sugars in brewing, especially by new homebrewers.

Malt: Processed barley that has been steeped, germinated, and dried to convert starches into fermentable sugars.

Maltase: The enzyme responsible for converting maltose into glucose during fermentation.

Malting: The process of steeping, germinating, and drying grains, typically barley, to produce malt.

Mash: The hot water steeping process in which the enzymes in malt break down starches into fermentable sugars.

Mash Kettle: The kettle used to boil a portion of the mash in decoction brewing.

Mash Tun: A vessel used for mashing, in which the crushed malt is mixed with hot water to convert starches into sugars.

Mashing Out: The process of raising the mash temperature to halt enzymatic activity and prevent further starch conversion.

Mead: A beverage produced by fermenting honey.

Melanoidins: Strong flavor compounds produced by the browning reactions, contributing to the color and flavor of beer.

Metheglin: Mead flavored with spices.

Microbrewery: A brewery that produces a relatively small volume of beer, typically less than 15,000 barrels per year, with a significant portion of the beer sold off-site.

Micron: A unit of length equal to one-thousandth of a millimeter.

Mildew: A fungal growth that appears as a thin, whitish layer on organic matter, including plants.

Milling: The process of grinding malt into grist to facilitate the extraction of sugars during mashing.

Mineral: Any naturally occurring element or compound found in the mineral kingdom, often present in water used for brewing.

Modification: The physical changes that occur in barley during malting, including the degradation and simplification of its components.

Modified Malts: Malts that have undergone a specific level of modification during the malting process.

Mold: A fungal growth that appears as a wooly or mildewy layer on various organic materials.

Mouthfeel: The tactile sensations and texture perceived in the mouth while drinking beer, including carbonation, fullness, and aftertaste.

Musty: A moldy or mildewy character that can be perceived as an off-flavor in beer, resulting from cork or bacterial contamination.

Myrcene: One of the essential oils found in hops, contributing to the hop aroma and flavor in beer.

Noble Hops: Traditional European hop varieties known for their characteristic flavor and aroma.

Nonflocculating Yeast: Bottom-fermenting yeast strains that do not clump together during fermentation.

Nonhopped: Referring to any beer or malt extract that has not come into contact with hops.

Northern Brewer: A hop variety grown in England and the northwestern United States, known for its alpha acid content.

Nose: A term used in tastings to describe the overall fragrance, aroma, and bouquet of a beer or wine.

Nuclease: An enzyme that breaks down nucleic acids into nucleotides.

Nugget: A hop variety grown in North America, typically with a higher alpha acid content.

Nutrients: Essential compounds, such as nitrogen and phosphorous, needed by yeast for healthy fermentation.

Oasthouse: A facility on a farm where hops are dried and baled after harvesting.

Off-flavor: A taste or aroma in beer

that is inconsistent with the style or is considered unpleasant, often caused by poor sanitation, excessive aging, or oxidation.

Oktoberfest: A German festival and beer style characterized by lagering and a specific starting gravity.

Old Ale: A dark English ale meant to be aged for at least a year, known for its acidic flavor resulting from lactic acid produced during aging.

Original Gravity (OG): The specific gravity of the wort before fermentation, indicating the amount of dissolved solids and sugars.

Osmotic: Relating to the pressure differential between two solutions of different concentrations when separated by a semi-permeable membrane.

Over-priming: The act of adding too much priming sugar to beer before bottling or kegging, resulting in overcarbonation or potentially bottle explosions.

Oxidases: Enzymes involved in oxidation reactions, facilitating the addition of oxygen to substances.

Oxidation: A chemical reaction in which a substance reacts with oxygen or an oxidizing agent, leading to flavor and aroma changes in beer.

Oxidized: Referring to beer that has been exposed to excessive oxygen, resulting in flavor problems and potential spoilage.

Oxygen: A colorless, odorless, and tasteless gas that constitutes a significant portion of the Earth’s atmosphere, used by yeast during fermentation.

Package: Refers to the containers used to market beverages, with packaged beer typically sold in bottles and cans, while beer sold in kegs is known as draught beer.

Palate: The upper part of the inside of the mouth associated with the sense of taste.

Pale Ale: A beer style that is amber in color, drier, and hoppier compared to other beers.

Papain: A proteolytic enzyme derived from papaya latex, used by brewers to increase beer stability.

Partial Mash: A brewing technique that combines malt extract with a small amount of mashed grains.

Pasteurization: The process of exposing packaged beer to a specific temperature (140°F or 60°C) for a defined duration to kill microorganisms and extend shelf life.

Pectin: A group of substances found in fruits and vegetables that can cause haziness in beer.

Pediococcus: A type of bacteria that is often considered a contaminant in beer but desired in certain beer styles like Lambic. It can produce diacetyl, contributing a buttery or butterscotch aroma and flavor.

Pepsin: A proteolytic enzyme produced in the stomach of higher animals, used for digestion.

Peptidase: A proteolytic enzyme that breaks down small proteins into amino acids.

Peptide: A chain of amino acids joined by peptide bonds.

Peptize: The process of bringing substances into a colloidal solution.

Peptonize: To digest or dissolve through the action of a proteolytic ferment.

pH: The measure of acidity or alkalinity in a solution, expressed on a logarithmic scale from 0 to 14.

Phenol: A class of aromatic hydroxyl compounds that can contribute to certain flavors and aromas in beer.

Pilsner: The original beer style from Pilsen, Czech Republic, known for its light color and hoppy character.

Pitch: The act of adding yeast to unfermented wort.

Pitching: The process of adding yeast to the wort to initiate fermentation.

Plastic: A material capable of being deformed without rupture, often used for beer bottles and packaging.

Points per Pound per Gallon (PPG): A unit used by homebrewers to measure the total soluble extract of malt, indicating the change in specific gravity per pound of malt in a known volume of water.

Polymerase: A group of enzymes involved in the synthesis of nucleic acids.

Polypeptide: A chain of amino acids joined by peptide bonds.

Porter: A smooth and sweet dark beer style.

Potential Alcohol: The estimated alcohol content a final brew will have, based on the pre-fermentation sugar content.

ppm: Abbreviation for parts per million, used to express concentrations in water and other substances.

Precipitate: To separate solid substances from a solution, or the solid substance itself.

Pressurizing: Applying pressure to a fermentation vessel to capture naturally produced carbon dioxide.

Primary Fermentation: The initial phase of fermentation marked by the evolution of carbon dioxide and the formation of krausen.

Priming: The process of adding a small amount of fermentable sugar, such as corn sugar or priming sugar, to the fermented beer before bottling or kegging. This sugar is consumed by the remaining yeast, resulting in the production of carbon dioxide, which carbonates the beer.

Priming Sugar: The sugar added to the fermented beer just before bottling or kegging to provide the yeast with additional fermentable sugars for carbonation.

Prohibition: A period in the United States from 1920 to 1933 when the sale, production, importation, and transportation of alcoholic beverages were prohibited by law. It was instituted by the Eighteenth Amendment to the U.S. Constitution and repealed by the Twenty-first Amendment.

Protease: A type of enzyme that breaks down proteins into smaller peptides or amino acids.

Protein: A class of compounds consisting of amino acids joined together by peptide bonds. Proteins are essential components of living organisms and are present in malt and other brewing ingredients.

Proteolysis: The process of breaking down proteins into smaller peptides or amino acids through the action of proteolytic enzymes.

Pseudomonas: A genus of bacteria that can be found in various environments, including beer. Certain species of Pseudomonas can cause off-flavors in beer, such as a buttery or rancid aroma.

Pump: A device used in brewing to transfer liquid from one vessel to another, such as from the mash tun to the brew kettle or from the fermenter to the packaging container.

Punt: The indentation at the bottom of some bottles, often found in wine bottles. The punt helps to strengthen the bottle and facilitate pouring.

Pure Culture: The growth of a single type of microorganism in a controlled environment, free from contamination by other organisms.

Pyruvate: An important molecule in fermentation and metabolism. It is the end product of glycolysis and serves as a precursor for the production of ethanol and other compounds during yeast fermentation.

Quaff: To drink deeply or heartily.

Rack: The process of transferring beer from one vessel to another, typically from the primary fermenter to a secondary fermenter or from a fermenter to a keg or bottling bucket. This helps separate the beer from sediment or trub.

Racking Cane: A plastic tube with an arced end used in siphoning beer. The arced end allows the tube to stay above the sediment, ensuring cleaner transfer of the liquid.

Radicle: The embryonic root of a germinating seed.

Rauchbier: A beer style from Germany, known for its smoky flavor derived from using smoked malts. It is often amber in color and has a distinct aroma and taste.

Real Ale: A style of beer found primarily in England, where it undergoes a secondary fermentation in the container from which it is served. It is typically served without the use of added carbon dioxide or forced carbonation.

Reinheitsgebot: The German Beer Purity Law, originally enacted in 1516, which stipulated that beer could only be brewed using water, barley, and hops. Yeast was later added to the list of allowed ingredients after its role in fermentation was discovered.

Residual Alkalinity: A measurement of the ability of the mash to resist changes in pH, which can affect the efficiency of enzymatic reactions during mashing.

Residual Sugar: The amount of sugar remaining in the beer after fermentation, which contributes to the beer’s sweetness and body.

Resin: A sticky substance produced by certain plants, such as hops, that contains bitter compounds known as alpha acids. Resin from hops is responsible for the bitterness in beer.

Rest: In brewing, a period during the mash process where the temperature is held at a specific level to activate certain enzymes or promote specific reactions.

Restriction Enzyme: An enzyme that can recognize and cut DNA at specific sequences. It is often used in genetic engineering and DNA manipulation.

RIMS (Recirculating Infusion Mash System): A type of brewing system used by homebrewers that involves recirculating the mash through a heat exchanger to maintain precise temperature control during mashing.

Roasted Barley: Unmalted barley that has been roasted to create a dark color and impart flavors such as coffee and chocolate. It is commonly used in stouts and porters.

Roasted Malt: Malt that has been kilned or roasted to develop darker colors and flavors. It adds complexity and roasted notes to the beer.

Rousing: Agitating or stirring the beer during fermentation to encourage yeast activity, mix flavors, or promote clarification.

Ruh: A German term referring to the period of storage or maturation after the main fermentation. It allows the flavors to develop and the beer to clarify before packaging.

Saaz: It’s a place in the Czech Republic known for its beer.

Saccharification: It’s like a magic trick where enzymes turn starch into sugar.

Saccharometer: This gadget helps you see how much sugar is in a solution. It’s like a hydrometer.

Saccharomyces: This is a type of yeast used to make beer and bread. It loves to eat sugar!

Saison: This is a type of Belgian beer that’s amber-colored, fruity, and has about 5% alcohol. It also needs to rest in a bottle for at least 90 days.

Salt: It’s a class of compounds, but mostly it means table salt (NaCl).

Sanitize: Cleaning up your brewing tools to keep bad bacteria away.

Saponifi-: This is like a science experiment where a fatty acid reacts with something like caustic soda to form soap and alcohol.

Sarcina: A microorganism that’s not your brewing friend.

Saturated Solution: This is when a liquid can’t hold any more dissolved stuff at a certain temperature.

Secondary Fermentation: The next stage after the first fermentation, where the beer gets clearer and more flavors develop.

Sediment: It’s like the leftovers at the bottom of your beer vessels after fermentation.

Seed Yeast: Yeast that kicks off the fermentation.

Session Beer: A beer that’s light enough to enjoy more than one in a sitting.

Siphoning Tube: A food-safe plastic tube to help you move beer from one container to another.

Six-row Barley: It’s a type of barley with six rows of grains but gives less extract compared to the two-row variety.

Skimming: It’s like fishing for the yeast that forms on top of the brew during fermentation so you can use it again later.

Slurry: A mix of water and solid stuff that can’t dissolve.

Small: A term used for breweries that produce 6 million barrels of beer or less per year.

Smoked Malt: A malt that tastes smoky because it’s dried over open fire.

Soap: It’s a type of salt that comes from a fatty acid.

Soft Water: Water that’s free of calcium, magnesium, chlorine, iron, and other hard water elements.

Solubility: How much stuff can dissolve in a certain amount of solution.

Solute: The stuff that gets dissolved in a liquid.

Solution: A smooth mix formed when you dissolve something in a liquid, gas, or solid.

Solvent-like Flavor: A taste that’s similar to acetone or lacquer thinner, often from fermenting at high temperatures.

Sorghum: A cereal grain that’s also friendly to people who can’t have gluten.

Sour: A tart, acidic taste, sometimes because of certain bacteria.

Spalt: A place in Germany known for its beer.

Sparge: Like giving grains or hops a shower to rinse out the flavors.

Specific Gravity: This measures how much dissolved sugar is in your wort or beer, compared to water.

Spicy: A term to describe some ales that remind you of spices, thanks to the hops.

Spigot: It’s a faucet to control the flow of liquids from a barrel

Spiles: Little wooden plugs to close the holes in barrels.

Standard Reference Method (SRM): It’s a method brewers use to measure how dark or light a beer is.

Starch: A tasteless, white substance that turns blue with iodine. It’s a complex carbohydrate.

Starter: This is about getting yeast cells activated before adding them to the wort.

Steam Beer: A type of beer from California that’s top-fermented and really fizzy.

Steeping: Soaking grain in water to get it ready for germination.

Step Infusion: A mashing method where hot water is added to raise the temperature of the mash.

Sterile: Free from all microorganisms, including bacteria.

Sterols: These are steroid alcohols found in plant and animal fats.

Stout: A dark, sharp tasting ale originally made in Britain.

Stuck Fermentation: When the fermentation stops before the yeast has eaten all its sugars.

Substrate: The stuff that an enzyme works on.

Sucrose: A type of sugar made of fructose and glucose. It’s usually found in cane sugar.

Sugar: A group of sweet carbohydrates that have up to three simple sugar units.

Sulfur: An aroma that smells like rotten eggs or burnt matches. It can be caused by certain yeasts or exposure to light.

Suspension: When solid particles are mixed but not dissolved in a fluid or another solid.

Tannin: A strongly astringent substance obtained from gall nuts, sumac, etc., used in chillproofing of beer. Also present in hops and malt in small amounts.

Tannins: Astringent polyphenol compounds that can cause haze and/or join with large proteins to precipitate them from solution. Tannins are most commonly found in the grain husks and hop cone material.

Tannins: A group of organic compounds contained in certain cereal grains and other plants. Tannins are present in the hop cone. Also called “hop tannin” to distinguish it from tannins originating from malted barley. The greater part of malt tannin content is derived from malt husks, but malt tannins differ chemically from hop tannins. In extreme examples, tannins from both can be perceived as a taste or sensation similar to sampling black tea that has steeped for a very long time.

Tap: A device that is attached to a keg or cask in order to control the flow of the beer.

Temperature Rests: Temperature Rests during the beer making process allows the brewer to adjust fermentable sugar profiles so as to influence characteristics of the resulting beer.

Template: A molecule that serves as the pattern for synthesizing another molecule.

Terminal gravity: A term used to define the specific gravity after a beer has fermented and aged appropriately. A synonym that is commonly used is final gravity.

Tertiary fermentation: This is a fermentation that is carried out in bottles as a conditioning technique.

Tettnang: A German hop variety in the 3­5 percent alpha acid range.

Thermo-Bacteria: Heat resistant microorganisms undesirable in brewing.

Thermometer: A tool for measuring temperature. Thermometers specifically made for brewing use alternative materials to mercury (such as alcohol) as a precautionary measure, so that if the thermometers break, no poisonous chemicals will infect the beer.

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

Toasted malt: A pale malt that is kilned for varying amounts of time, at different temperatures in order to produce certain “toasty” flavor characteristics.

Tonne: A wooden cask that is 2.2 barrels (68.2 gallons/259.1 L) in volume.

Top Fermentation: One of the two basic fermentation methods characterized by the tendency of yeast cells to rise to the surface of the fermentation vessel. Ale yeast is top fermenting compared to lager yeast, which is bottom fermenting. Beers brewed in this fashion are commonly called ale or top-fermented beers.

Topping up: A term used to define the addition of water after boiling a concentrated wort or extract; or the practice of adding water after primary fermentation in order to decrease the head space and prevent air contamination.

Transfer: Moving fermented ale from one container to another.

Trappist beer: Beer brewed from any of the seven monasteries in Belgium and the Netherlands. These beers are all top-fermented, bottle conditioned and range in alcohol content from 4 to 12% by volume. They are renowned for their fruity flavor and spritzy carbonation.

Tripel: A strong Belgian ale that is pale in color and high in alcohol (upwards of 7% by volume).

Trub (G): The haze or flock appearing in wort by boiling or cooling.

Trub (trub or troob): The sediment at the bottom of the fermenter consisting of hot and cold break material, hop bits, and dead yeast.

Trub: Wort particles resulting from the precipitation of proteins, hop oils and tannins during the boiling and cooling stages of brewing.

Try Cock/Test Cock: Sampling device.

Turbidity: Sediment in suspension; hazy, murky.

U.K. gallon: A synonym for imperial gallon, the English measurement equal to ~1.2 U.S. Gallons. Similarly, the fractional volumes of U.K. pints and quarts are also the equivalent volume greater than the U.S. measurement.

Ullage: A term that refers to calculating the headspace of a cask, keg or barrel.

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.

Undermodified malt: Malt containing barley or other grains that have been kilned or dried out in a way that prevented all the enzymes from transforming into proteins.

Underoxygenated: A term used to describe worts that have not been sufficiently aerated for fermentation. Yeast need an adequate amount of oxygen to effectively convert sugar to alcohol (and CO2).

Uni-tanks: A type of fermenter that is used for both primary fermentation and conditioning.

Unload: The process of emptying the steeped malts from the steeping vessel.

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

Vat: Usually a fermenting or storage vessel.

Vent Hole: A small hole to allow air to escape.

VGA: An American hop variety providing medium bitterness.

Vienna lager: A style that derives from Austria that is amber in color. In modern day, Mexico has made this style popular through beers like Dos Equis Amber.

Viscosity: 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.

Viscosity: As an adjective, this descriptor refers to body and mouthfeel, but it literally refers to the resistance of liquid (beer) to flow ‹ i.e. its thickness.

Vitamin: Any one of a group of constituents of most foods in their natural state which are essential for normal nutrition.

Volatile: In chemistry, any one of those acids which can be distilled from an aqueous solution at atmospheric pressure, such as acetic, and butyric acid. Fixed acids such as tartaric, phosphoric, etc., cannot be removed by distillation.

Volatile acids: Acids in beer and other beverages that are decreased through evaporation, chemical treatment and fermentation.

Volatile Compounds: Chemicals that have a high vapor pressure at ordinary room temperature which causes large numbers of molecules to evaporate and enter the surrounding air.

Volstead Act: Also known as the national prohibition act, was enacted to carry out the intent of the Eighteenth Amendment, which established prohibition in the United States.

Volumes of CO2: The measurement of CO2 dissolved in a beer and is an indication of the carbonation level.

Vorlauf: At the outset of lautering and immediately prior to collecting wort in the brew kettle, the recirculation of wort from the lauter tun outlet back onto the top of the grain bed in order to clarify the wort. German word referring to the process of recirculating wort through the grain bed.

Wallop: A slang British term used for mild beers with low alcohol.

Warming taste of ethanol and higher alcohols: This can be described as spicy and vinous in character. The higher the ABV of a beer, often the larger the mouthfeel it has. Alcohol can be perceived in aroma, flavor, and as a sensation.

Water: One of the four ingredients in beer. Some beers are made up by as much as 90% water. Globally, some brewing centers became famous for their particular type of beer, and the individual flavors of their beer were strongly influenced by the brewing water’s pH and mineral content. Burton is renowned for its bitter beers because the water is hard (higher pH), Edinburgh for its pale ales, Dortmund for its pale lager, and Plzen for its Pilsner Urquell (soft water, lower pH).

Wax: Any one of a class of substances of plant or animal origin, insoluble in water, partly soluble in alcohol, ether, etc., and miscible in all proportions with oils and fats. They consist of esters and often, in addition, free fatty acids, free alcohols, and higher hydrocarbons.

Weissbier: The German term for wheat beer. Weiss literally means white, and wheat beers are very pale in color.

Weizenbier: The German term for top-fermented wheat beers.

Wet Hopping: The addition of freshly harvested hops that have not yet been dried to different stages of the brewing process. Wet hopping adds unique flavors and aromas to beer that are not normally found when using hops that have been dried and processed per usual.

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

Wild yeast: Yeast that is naturally airborne. Originally, all beers were fermented with wild yeast.

Wort: The liquid obtained when malt enzymes attack a heated aqueous slurry of ground endosperm of malted and unmalted cereal. It’s also the malt-sugar solution that is boiled prior to fermentation. It is the bittersweet sugar solution obtained by mashing the malt and boiling in the hops, which becomes beer through fermentation. Wort can also be defined as unfermented ale or the sweet solution created by boiling malt, hops, and water. It is high in sugar and ferments when yeast is added.

Yard of Ale: A long neck glass that measures 3 feet (i.e., 1 yard) and holds about a quart of beer.

Yeast: A group of unicellular organisms of the family Saccharomycetaceae which ferment sugars to alcohol and carbon dioxide by virtue of its enzymes (Zymase). It’s a general term for single-celled fungi that reproduce by budding. Some yeasts can ferment carbohydrates (starches and sugars), and thus are important in brewing and baking. During the fermentation process, yeast converts the natural malt sugars into alcohol and carbon dioxide gas.

Yeast Cake: Living yeast cells compressed with starch into a cake, for use in brewing.

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

Yeast Energizer/Nutrient/Extract: Products used to reactivate or jump-start inactive yeast.

Yeast Nutrients: These are elements that can be added to a fermentation to promote yeast health and vitality. Homebrew supply shops sell pre-measured packages of yeast nutrients for small batches.

Yeast Pitching: The point in the brewing process in which yeast is added to cool wort prior to fermentation.

Yeast: Microbes used in brewing that convert sugars into alcohol and CO2.

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.

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.

Zymase: Enzymes in yeast that produce alcoholic fermentation by converting glucose to alcohols and carbon dioxide.

Zymology (or Zymurgy): The science of fermentation.

Zymurgy: The science of brewing and fermentation. Also the name of the American Homebrewers Association bi-monthly magazine.

Zythos: Greek name for barleywine.