FIELD: brewing industry.
SUBSTANCE: method of beer production includes wort boiling stage and fermentation stage and stage of isomerisation of hop-like alpha-acids into iso-alpha-acids. Isomerisation stage is carried out separately from the wort cooking in the wort kettle using one or more types of complexes of alkali-earth metal cations with charge more than +1 and chelating agents, selected from a group of amino acids, including salts thereof, in an aqueous process medium for isomerisation of alpha-acids, containing at least 60 vol % water from the total volume of the solvent. Total content of alpha-acids and iso-alpha-acids in the aqueous process medium is at least 0.1 wt %. Molar ratio of complex of alkali-earth metal cation (calculated on the basis of amount of alkali-earth metal) and the chelating agent to the total amount of alpha-acids and iso-alpha-acids in the aqueous process medium ranges from 20:1 to 1:20. Molar ratio of alkali-earth metal cations to the chelating agent in the aqueous process medium ranges from 20:1 to 1:20. Working temperature of the alpha-acid isomerisation process ranges from 323 to 368 K and the processing time ranges from 1 to 120 min. At isomerisation step, an aqueous mixture is obtained, containing iso-alpha-acid, which without further treatment or after further treatment is added to wort during beer boiling—before boiling, during wort cooking or after wort boiling—or to beer after the fermentation stage, wherein during beer boiling, from 4 mg/l to 100 mg/l of iso-alpha-acids is added.
EFFECT: group of inventions provides obtaining degree of utilization of alpha-acids 45–50 %.
18 cl, 1 ex
