Beer Brewing

Glossary

P

PALATE FULLNESS - See Body.

PASTEURIZATION - The application of heat to bottled, canned, kegged or bulk beer for a specific period of time for the purpose of stabilizing it biologically by killing microorganisms to prolong the shelf life of packaged beer.

pH - It is a numerical designation given to the acidity and alkalinity of an aqueous solution, on a scale of 1 to 14. Technically, pH is common logarithm of the reciprocal of the hydrogen-ion concentration of a solution. A pH value of 7 (pure water at 25°C) indicates neutrality, while values below 7 (7 to 1) indicate acidity and above 7 (7 to 14) indicate alkalinity.

PEPTIDASE - A proteolytic enzyme that breaks down large and medium-sized protein molecules into amino acids during mashing.

PEPTIDES - A class of proteins consisting of between two and thirty amino acid molecules bound by peptide bonds. Peptides enhance the viscosity, or fullness, of beer, may also oxidize to high-molecular weight polypeptides.

PEPTIZATION - The spontaneous dispersion of protein soils throughout the cleaning solution without mechanical agitation.

PEPTONIZING - The action of proteolytic enzymes upon protein, yielding albumin/proteoses, peptides and amino acids.

PHENOL - This structure is the building bloc of a large group of phenolic compounds (often referred to as polyphenols or simply "phenols"). Phenols are derived mostly from malt and to a lesser degree hops. Yeast produce phenols but the amounts are quite small. Generally speaking, S. cerevisiae produce more phenols than S. pastorianus and, wild strains of yeast or bacteria are often the cause of phenolic flavors. Spices used in specialty beers are known to contain phenolic compounds.

PHYSICAL STABILITY - A measure of the susceptibility to precipitation, suspension, or haze formation in bottled beer.

PHYTASE - An enzyme that reduces the mash pH be creating phytic acid from the phytin of the malt. This aids in saccharification, wort clarification, and fermentation.

PINT - Standard measure in which beer is served in the UK. Equivalent to 0.568 of a liter.

PITCHING - Adding yeast to the sterile wort to initiate fermentation.

PLATO, DEGREES - Commercial brewers' standard for the measurement of the density of solutions expressed as an equivalent weight of the solution (grams of sucrose per 100 grams of solution, measured at 20°C). It expresses the weight of any substance in solution as a percentage of the weight of that solution, based upon sucrose dissolved in pure water. A density that measures one °P means that 1% of the weight of the measured liquid is dissolved sugar. In other words, a density of 15° P indicates that there would be 15 grams of dissolved sugars in enough water to make 100 grams of solution.

POLYPHENOLS - Complex molecules that are responsible for astringent and bitter flavors as well as the haze formation in beer. In small concentrations phenolic compounds add character to beer whereas high concentrations impart off-flavors described as phenolic, medicinal or pharmaceutical. They are a major influence on color in beer and are found in greater concentrations in alkaline waters and dark beers. Tannins and lignins are well-known examples of polyphenol compounds.

PHOSPHATES - These molecules are the source of phytic acid created during malting and during decoction mashes. They contribute to the acidulation of the mash.

POLYSACCHARIDES - Carbohydrate complexes formed by the union of two or more monosaccharides.

PPM - Parts per million (mg/ml). It is a measurement of particles of matter in solution.

PRIMARY ATTENUATION - The attenuation measured at the end of primary fermentation.

PRIMARY FERMENTATION - The initial fermentation, during which most of the carbohydrates in the wort are assimilated and converted to ethyl alcohol and carbon dioxide gas. If no secondary fermentation is done, than all the carbohydrates are assimilated during primary fermentation.

PRIMING - The addition of small amounts of fermentable sugars (preferably corn sugar or syrup) to fully fermented beer before bottling or kegging to induce secondary fermentation and thus carbonate the beer.

PRIMING SOLUTION - A solution of sugar in water added with yeast to the aged beer at bottling to induce fermentation (bottle-conditioning).

PROTEASE - A malt enzyme that develops in barley during germination and is capable of degrading complex proteins into polypeptides and amino acids.

PROTEIN - A complex chain of amino acids held together by peptide links. Proteins are respon­sible for the head retention and body of beer and partially for its haziness.

PROTEIN REST - A stage of the mashing process during which complex proteins are decomposed by proteolytic enzymes to progressively less complex fractions.

PROTEINASE - This proteolytic enzyme works to break large protein molecules down into medium-sized proteins during mashing.

PROTEOLYSIS - The reduction of protein by proteolytic enzymes to fractions.