Terminology

Here is a list of terminology that will likely be used in various blog posts. The terminology is from the glossary of John Palmer's book "How to Brew". If you're interested in brewing, I highly recommend buying a copy of this book as it has been a great reference for me. The book is also available online at http://www.howtobrew.com/.


Adjunct - Any non-enzymatic fermentable. Adjuncts include: unmalted cereals such as flaked barley or corn grits, syrups, and sugars.

Aerate - To mix air into solution to provide oxygen for the yeast.

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

Attenuation - The degree of conversion of sugar to alcohol and CO2.

Cold Break - Proteins that coagulate and fall out of solution when the wort is rapidly cooled prior to pitching the yeast.

Conditioning - An aspect of secondary fermentation in which the yeast refine the flavors of the final beer. Conditioning continues in the bottle.

Dextrose - Equivalent to Glucose, but with a mirror-image molecular structure.

Dimethyl Sulfide (DMS) - A background flavor compound that is desirable in low amounts in lagers, but that at high concentrations tastes of cooked vegetables.

Enzymes - Protein-based catalysts that effect specific biochemical reactions.

Esters - Aromatic compounds formed from alcohols by yeast action. Typically smell fruity.

Fermentation - The total conversion of malt sugars to beer, defined here as three parts, adaptation, primary, and secondary.

Finings - Ingredients such as isinglass, bentonite, Irish moss, etc, that act to help the yeast to flocculate and settle out of finished beer.

Flocculation - To cause to group together. In the case of yeast, it is the clumping and settling of the yeast out of solution.

Gelatinization - The process of rendering starches soluble in water by heat, or by a combination of heat and enzyme action, is called gelatinization.

Germination - Part of the malting process where the acrospire grows and begins to erupt from the hull. 
 
Grist - The term for crushed malt before mashing.

Gravity - Like density, gravity describes the concentration of malt sugar in the wort. The specific gravity of water is 1.000 at 59F.

Hops - Hop vines are grown in cool climates and brewers make use of the cone-like flowers. The dried cones are available in pellets, plugs, or whole.

Hot Break - Proteins that coagulate and fall out of solution during the wort boil.


International Bittering Units (IBU) - A more precise unit for measuring hops. Equal to the AAU multiplied by factors for percent utilization, wort volume and wort gravity.

Irish Moss - An emulsifying agent, Irish moss promotes break material formation and precipitation during the boil and upon cooling.

Krausen (kroy-zen) - Used to refer to the foamy head that builds on top of the beer during fermentation. Also an advanced method of priming.

Lager - A beer brewed from a bottom-fermenting yeast and given a long cool fermentation.

Lauter - To strain or separate. Lautering acts to separate the wort from grain via filtering and sparging.

Mash - The hot water steeping process that promotes enzymatic breakdown of the grist into soluble, fermentable sugars. 

Pitching - Term for adding the yeast to the fermenter.

Primary Fermentation - The initial fermentation activity marked by the evolution of carbon dioxide and Krausen. Most of the total attenuation occurs during this phase.

Priming - The method of adding a small amount of fermentable sugar prior to bottling to give the beer carbonation.

Racking - The careful siphoning of the beer away from the trub.

Saccharification - The conversion of soluble starches to sugars via enzymatic action.

Sanitize - To reduce microbial contaminants to insignificant levels.

Secondary Fermentation - A period of settling and conditioning of the beer after primary fermentation and before bottling.

Sparge - To sprinkle. To rinse the grainbed during lautering.

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. 

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

Wort (wart or wert) - The malt-sugar solution that is boiled prior to fermentation.