The penetration of a liquid or solid into or through another liquid or solid, the particles that are absorbed being molecular or micellar in size. A few solid bodies have the power of taking up or absorbing gases, for instance, charcoal or activated carbon.

A product of alcohol metabolism that is more toxic than alcohol itself, acetaldehyde is created when the alcohol in the liver is broken down by an enzyme called alcohol dehydrogenase. The acetaldehyde is then attacked by another enzyme, acetaldehyde dehydrogenase, and another substance called glutathione, which contains high quantities of cysteine (a substance that is attracted to acetaldehyde). Together, the acetaldehyde dehydrogenase and the glutathione form the nontoxic acetate (a substance similar to vinegar). This process works well, leaving the acetaldehyde only a short amount of time to do its damage if only a few drinks are consumed.

A hydrogen containing substance which will dissociate on solution in water to produce one or more hydrogen ions (H+). This susually resuilts in an "active", sharp or bitter tatse.

The beginnings of the plant shoot in germinating barley.

Enzymes, preservatives and antioxidants which are added to simplify the brewing process or prolong shelf life.

Fermentable material used as a substitute for traditional grains, to make beer lighter-bodied or cheaper. Class includes any non-enzymatic fermentable. Adjuncts include: unmalted cereals such as flaked barley or corn grits, syrups, and sugars.

An organism, such as top fermenting ale yeast, that needs oxygen to metabolize.

The water soluble colloidal carbohydrate of the red seaweed, Gelidium; forms gels with as little as one part to 500 of water. It is used in preparing bacteriological media.

Any of a series of organic compounds containing one or more hydroxyl OH) groups. In beverages, ethyl alcohol or ethanol is an intoxicating by-product of fermentation, which is caused by yeast acting on sugars in the malt. Alcohol content is expressed as a percentage of volume or weight.

(ABV) Amount of alcohol in beer in terms of percentage volume of alcohol per volume of beer. So a 7 percent ABW beer would be a 9 percent ABV beer. If for some reason you want to convert from ABV to ABW, multiply the ABV percent by 0.80.

(ABW) Amount of alcohol in beer measured in terms of the percentage weight of alcohol per volume of beer, i.e., 3.2% alcohol by weights equals 3.2 grams of alcohol per 100 centiliters of beer. (It is approximately 20% less than alcohol by volume.) So a 7 percent ABW beer would be a 9 percent ABV beer. If for some reason you want to convert from ABV to ABW, multiply the ABV percent by 0.80.

A beer brewed from a top-fermenting yeast with a relatively short, warm fermentation. The top fermenting yeast perform at higher rates at this warmer temperatures than do yeast's used to brew lager beer, and their byproducts are more evident in taste and aroma. Fruitiness and esters are often part of an ale's character. In these malt beverages, the wort is fermented with strains of yeast which tend to rise to the top of the vessel and form a yeast head at the end of fermentation.

Refers to the capability of water to neutralize acid. This is really an expression of buffering capacity. A buffer is a solution to which an acid can be added without changing the concentration of available H+ ions (without changing the pH) appreciably. The combining power of a base measured by the maximum number of equivalents of an acid with which it can react to form a salt.

A relatively new term in America. "All malt" refers to a beer made exclusively with barley malt and without adjuncts.

A homebrewing measurement of hops. Equal to the weight in ounces multiplied by the percent of alpha acids.