Factors Contributing to Wort Nitrogen. I. Contributions of Malting and Mashing, and Effect of Malting Time

Abstract

The relative contributions of malting and mashing to total and free amino N in worts of two-rowed and six-rowed barleys were determined. The effects of malting time on N levels in wort also were studied. Nitrogen released during mashing was expressed as the difference between wort N and malt-soluble N extracted at 0° C to minimize enzymatic hydrolysis. In wort, 70–76% of total N and 68% of free amino N originated with the malt. Piroline malts attained maximal soluble N levels in 2–3 days at 16°C; barker malts reached these levels in 3–4 days. Gibberellic acid treatment stimulated N release, but did not shorten the malting time required for maximal levels. Nitrogen released during mashing increased slowly with mailing time. Relatively high levels of total and free amino N were released during mashing of steeped barleys and 1-day malts. The results indicate that malt per se is the major source of total and free amino N in wort, and that proteolysis during mashing may account for even less than the 25–30% found by analysis.