Studies were carried out with 3 barley varieties. Eli, Wisa and Bido, to determine the effect of varying the germination time on the nitrogenous components of the malt as reflected in the soluble nitrogen, alpha amino nitrogen and individual amino acids in the resulting wort. The protein content of the malt decreased and the wort soluble nitrogen increased steadily during a germination period of 10 days. Alpha amino nitrogen increased rapidly during the first 4 days of germination, reaches a maximum between the 7th and 8th days and then decreased. Alpha amino nitrogen as percent of the total wort nitrogen, already relatively high after only 24 h germination, increased up to the 4th day and then decreased. Very similar results are obtained for each of the amino acids. A germination time of at least 4 days was required in order to produce malts rich in amino acids, and consequently, exhibiting the required brewing properties including fermentation rate, yeast reproduction and fusel oil formation.
Keywords: amino acid barley germination malt nitrogenous compound wort