A semi-transparent, whitish and very pure form of gelatine, prepared from the air-bladders of certain fish, originally sturgeons, now largely cod, ling and carp.

pH value at which the electrical charge of an amino acid is zero.

Isomerized form of alpha acids from hops. Isohumulone content is related to the hop bitterness of beer.

One-half barrel, or 15.5 U. S. gallons. A half keg or, 7.75 U. S. gallons, is referred to as a pony-keg.

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

A stove or furnace for hardening, burning or drying materials, such as bricks, grains, or hops.

Used to refer to the foamy head that builds on top of the beer during fermentation. Also an advanced method of priming.

The addition of a small proportion of partly fermented wort to a brew during lagering. Stimulates secondary fermentation and imparts a crisp, spritzy character.

The period of adaptation and rapid aerobic growth of yeast upon pitching to the wort. The lag time typically lasts from 2-12 hours.

Beers produced with bottom fermenting yeast strains, at colder fermentation temperatures than ales. This cooler environment inhibits the natural production of esters and other byproducts, creating a crisper tasting product.

From the German word for storage. Refers to maturation for several weeks or months at cold temperatures (close to 0C /32F) to settle residual yeast, impart carbonation and make for clean round flavors.

To run the wort from the mash tun. From the German word to clarify. A lauter tun is a separate vessel to do this job. It uses a system of sharp rakes to achieve a very intensive extraction of malt sugars.

Vertical and usually cylindrical, straining tank having a false bottom for separating the wort from the spent grains.

See mash tun.

The separation of sweet wort from spent grains