AAU (Alpha Acid Units) - A measure of bitterness.
ABV (Alcohol by Volume) - A measurement of the percent of alcohol present in a volume of liquid.
Adjunet - An unmalted fermentable ingredient, such as honey or sugar. To increase the alcohol or add flavor. Adjunct grains such as corn and rice are used to lighten the flavor of the beer.
Alcohol - A byproduct of fermentation. It is produced when yeast consumes the fermentable sugars.
Ale - A beer made with top fermenting yeast. They are fermented between 68-75͒F. Ales absorb some of the byproducts from the fermentation which can cause a fruity or estery nose or flavor.
Alpha Acid - These come from the soft resin of the hop flower. They are made of humulone, ad-humulone and co-humulone.
Anaerobic - An organism that can live without atmospheric oxygen.
Barley - A cereal grain that is malted and used in the mash for making beer.
Barrel - A unit of measurement used by brewers. In Britain, a barrel holds 36 imperial gallons (1 imperial gallon = 4.5 liters), or 1.63 hectoliters. In the United States, a barrel holds 31.5 US gallons (1 US gallon = 3.8 liters) or 1.17 hectoliters.
Bittering Hops - Hops added to the boil with 45-60 minutes left. These are responsible for the bitterness of a beer.
Brew Kettle - The vessel that the boil takes place in.
Brewpub - A pub that makes its own beer and sells at least 50% on premises.
Bright Beer - Finished beer that is prepared to be bottled or kegged and served. This is the last stage in the brewing process before packaging.
Candi Sugar - Made by superheating and then cooling a highly concentrated sugar solution. Pale candi syrup is much darker than sucrose or invert sugar syrup. Belgian brewers prefer to use candi sugar, in either solid or syrup form, because it contributes to good head retention in a high-gravity, lightly hopped beer.
Caramel Malt - A sweet, coppery malt which imparts both color and flavor to beer. Gives a golden color and a nutlike flavor to beer. It is used frequently in darker ales.
Centrifugation - A clarification method using centrifugal force to strain and clarify the wort during its cooling stage and the finished beer prior to racking.
Chill Haze - A cloudiness that appears in beer when it gets cold. It is a result of proteins and polyphenols combining as a result of hydrogen bonding. The haze disappears as the beer warms up.
Chill Proof - By adding certain clarifiers to beer, it prevents chill haze by precipitating out the haze causing agents.
Craft Beer - Beers made by small, independent brewers with only traditional brewing ingredients such as malt, hops, yeast and water, and brewed with traditional brewing methods.
Crystal Malt - When fresh malt is carefully dried at warm temperatures, some of the starches are converted to sugars which crystallize within the grains. When these crystal malts are used in brewing, they add sweetness, body and a reddish-gold color to the beer.
Decoction - Exhaustive system of mashing in which portions of the wort are removed, heated, then returned to the original vessel.
Dextrin - The unfermentable carbohydrate produced by the enzymes in barley.
Diacetyl - A natural byproduct of yeast. It can have the flavors of butter or butterscotch.
DMS (Dimethyl Sulfide) - A sulfur compound that can be a desired flavor in lagers, but not in ales. DMS can be created by bacterial infection, or it can be created during the boil and is removed by vaporization. If the wort is not cooled quickly then it will dissolve back into the wort.
Draught/draft - Beer that is served from the cask, keg or barrel. Draught can be pasteurized, filtered or cask-conditioned, but bottled or canned beer is not, but definition, draught. The word means "drawn" or pulled from the cask by a pump.
Dry Beer - Described as having less aftertaste, it sometimes had almost no taste at all. It is created by a process that ferments virtually all the sugars in the beer. This type of beer was first brewed at Asahi Brewery of Japan in the late 80's.
Dry Hopping - Adding hops after the boil or even in the cask to increase hop aroma and flavor. This is most often seen in various types of ales, but not in lagers.
Estery - Aroma or flavor of fruit or flowers in beer. This can be caused by certain yeast strains or higher temperature of fermentation.
Fermentation - The reaction of the yeast consuming the sugars in the wort. This process creates ethyl alcohol and carbon dioxide.
Fining - Materials added to beer during secondary fermentation to help settle out the yeast and other particulates.
Finishing Hops - Hops added near the end or after the boil to add aroma and flavor. They do not tend to add bitterness.
Firkin - Unit of measure. 1 Firkin = 9 Imperial Gallons
Flocculation - The clumping, gathering or fallout of yeast cells after fermentation. Different yeast strains have different levels of flocculation.
Grist - A term for milled grains.
Heat Exchanger - A device to rapidly cool wort. Usually copper tubing that has cold water running through it. Sometimes 2 tubes, one inside the other, with wort going through one and cold water going through the other.
Helle - German wheat beer.
Hops - They come from the Humulus Lupulus plant or vine. It is the female flower that is used in brewing. They come in several forms: whole, pellet, and plug. Hops are what makes beer bitter.
Hydrometer - A device that measures specific gravity (SG) of a liquid. Hydrometers are usually calibrated for measurements at 60͒ F.
IBU (International Bitterness Unit) - A number that denotes the bitterness of the beer. The higher the IBU the more bitter the beer.
Infusion - Soaking or steeping grains in water or wort to transfer the flavors from the grain.
IPA (India Pale Ale) - A strong, hoppy pale ale. The style originated in Britain in the 19th century, and had a high alcohol content and hopping rate, allowing it to survive the long sea voyage to India.
Keg - A large metal (stainless steel) vessel that contains beer. They come in various sizes: 2.5 gallon, 5 gallon, 7.75 gallon, and 15.5 gallon. Import kegs are usually 13.2 gallons (50 liters).
Lager - Beer made with bottom fermenting yeast. Lager is fermented at lower temperatures and usually takes longer to ferment than ales. Since the fermentation is at low temperatures, the yeast byproducts are reduced and a cleaner, more crisp beer is the result.
Lagering - The process of aging beer at low temperatures, usually under 50͒F. This process takes anywhere from weeks to months.
Lauter Tun - A vessel where mash settles and grains are strained out of the sweet wort.
Liquor - The brewer's word for water used in the brewing process, as included in the mash or, used to sparge the grains after mashing.
Lovibond - A measurement of color. The scale starts at 0 and goes to over 500. The higher the number, the darker the color.
Lupulin - A yellow resinous powder found on the female hop cone that contains the bittering principle used in making beer.
Malt - (noun) Grain that has been matled. (verb) The malting process consists of wetting the grain and allowing it to germinate. During the germination, some of the starches in the grain get converted to sugars, while others become simple soluble starches and other enzymes. The grain is then dried and tumbled to knock the beginnings of roots off. The grain is then kilned to dry it thoroughly and caramelize some of the sugars like in crystal malt or blacken it like a black patent malt.
Malt Extract - Sweet wort that has been reduced to a syrupy liquid or dried into a powder.
Maltose - Water soluable, fermentable sugar from malt.
Mash - (verb) Release of sugars from grains into water. (noun) The mixture resulting from mashing.
Microbrewery - A brewery that produces less than 15,000 barrels per year.
Mouthfeel - How a beer feels in the mouth. Usually described as thin or full.
Noble Hops - Hallertauer Mittelfruh, Tettnanger Tettnang, Spalter Spalt, and Czech Saaz are the 4 main noble hops.
Original Gravity - The specific gravity of the wort before yeast is added.
Oxygenation - The addition of oxygen in the wort. This is done to help provide the yeast with oxygen for a healthy fermentation.
Pasteruization - Heating food or liquid to high temperatures to kill bacteria and other microorganisms. This also kills yeast.
Phenolic - A medicinal taste caused by volatile phenol compounds
Pin - Unit of measure. 1 Pin = 4.5 Imperial Gallons.
Pitching - Pitching yeast is adding yeast to wort. This is done around 70͒F. Pitching when the wort is too warm or too cold will kill the yeast.
Plato Degrees or Degrees Plato - A method or scale for measuring sugar in wort. It is an updated rendition of the Balling Scale.
Primary Fermentation - Vigorous fermentation where the yeast cells multiply and feed on the fermentable sugars in the wort, thus releasing carbon dioxide.
Priming - Addition of sugar to promote a secondary fermentation.
Racking - Transferring the wort into another container. Beer is racked from the primary fermenter to the brite tank.
Reinheitsgebot - The German Purity Law of 1516 that states the only 4 ingredients that an be included in beer are water, malted barley, yeast and hops.
RIMS (Recirculating Infusion Mash System) - Brewing set up that is quite popular among homebrewers.
Saccharification - A stage of the mashing process during which complex glucose chains are broken down into fermentable sugars, mainly maltose.
Saccharomyces Carlsbergensis - Lager or bottom fermenting yeast.
Saccharomyces Cerevisiae - Ale or top fermenting yeast.
Saccharomyces Uvarum - Lager or bottom fermenting yeast. Also known as Saccharomyces Carlsbergensis.
Secondary Fermentation - After primary fermentation, the beer is "racked" into another vessel for secondary fermentation. This helps remove some of the expired yeast which may give off negative flavors if left in.
Sparge - The recovery of sugars by spraying hot water on the grain bed.
Steam Beer - A beer produced by hybrid fermentation using bottom yeast fermented at top yeast temperatures. Fermentation is carried out in long shallow vessels called clarifiers, followed by warm conditioning and krausening.
Terminal Gravity - The specific gravity of the wort after fermentation has ended. Sometimes called final gravity.
Wit - "White" beer. It is a cloudy wheat beer, spiced with coriander and orange peel.
Wort - Wort is beer before it becomes beer. After the ingredients are boiled together, that mixtures is called wort.
Wort Chiller - A device to rapidly cool wort. Usually copper tubing that has cold water running through it. Sometimes two tubes, one inside the other, with wort going through one and cold water going through the other. Also called heat exchanger.
Yeast - Yeast is what makes the alcohol in beer. Yeast eats the sugars in the wort and produces alcohol and carbon dioxide.
Zymurgy - The branch of chemistry dealing with fermentation.
Definitions from https://brewdudes.wordpress.com/beer-making-terminology/