| Absolute weight |
A qualitative index of brewer’s barley and malt expressing the weight of 1000 grains in grams. It depends on the grain size and thickness.
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| Absorptive epithelium |
A row of cells between the grain endosperm and embryo. The soluble substances coming from the endosperm pass through it.
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| Acetaldehyde |
Acetic aldehyde – colourless liquid with pungent odour exhibiting high solubility in alcohol and water.
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| Acetic acid |
A monobasic carboxylic acid of the aliphatic homolog order. Colourless liquid with sharp odour and burning sour taste. It is normally present in small quantities in all wines. At higher concentrations, however, it causes an unpleasant and pungent acetic smell.
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| Acetoin |
An aliphatic ketone soluble in spirits and water. It is considered as one of the causes of cellar flavour in beer.
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| Acid taste |
A taste defect of beverages caused by an excessive amount of acids and by acids given off in the event of a pathological condition.
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| Acidity |
A basic chemical and organoleptic index of the content of non-volatile and volatile acids and acid salts.
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| Activated carbon |
A carbon adsorbent with highly developed porous structure. It can be used for the adsorption of aromatic components.
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| Adhesion |
Sticking together of the surface layers of heterogeneous solid substances occurring on molecular level. It is important for the application of resins and tank coatings of various composition.
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| Adjuncts |
Surrogates – unmalted grains used for enhancing the fermentation potential of mash.
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| Adsorbents |
Substances which take up different substances from liquids and gases. They are used for beer stabilization.
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| Adsorption |
Holding gaseous or liquid substances on the surface of solid bodies (adsorbents). Saturation with carbon dioxide can be attributed to adsorption and chemosorption. Adsorption can also explain the decrease in beer bitterness during filtration, removal of some flavour and aroma impairment caused by adsorbent treatment, and a number of other occurrences.
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| Aeration |
Technological operation of charging the wort with the oxygen needed for yeast reproduction.
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| Ageing |
A technological stage in beverage production which follows fermentation and aims to enhance composition and organoleptic properties. Physicochemical changes, i.e. sedimentation, clarification, carbonation, and chemical changes, i.e. oxidation, esterification, etc. are observed.
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| Alanine |
A nonessential amino acid. There are 2 structural isomers: alpha and beta alanine. The alpha alanine quantity in beer is around 50-100 mg/l.
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| Albumens |
Natural proteins found in all plant and animal tissues. On the one hand, their presence in beer contributes to flavour formation; however they also cause cloudiness.
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| Alcohol |
Hydrocarbon derivatives containing one, two or more hydroxyl groups in their molecules.
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| Alcohol content |
The ethyl alcohol percentage in water-alcohol mixtures. It can be expressed either as alcohol by weight, or as alcohol by volume.
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| Alcohol resistance |
The ability of microorganisms to grow in ethanol containing media. It is measured by the maximum alcohol concentration in the medium at which an organism demonstrates normal metabolic functions.
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| Alcoholic fermentation |
A biochemical process of sugar decomposition to ethanol and carbon dioxide aided by the enzyme systems of some microorganisms.
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| Alcoholic proof |
Alcoholic titer expressed in percentage and used to measure the alcohol content in beverages. It is based on Gay-Lussack’s alcohol measuring scale where zero is the alcohol degree of pure water and 100 of pure ethanol.
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| Aldehydes |
A class of organic compounds containing a carbonyl group bonded to an organic radical and a hydrogen atom.
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