Effects of Mashing Parameters on Mash β-Glucan, FAN and Soluble Extract Levels

摘要

To gain further technological knowledge of mashing, pilot scale mashing trials were carried out varying mashing programme (upward/isothermal mashing), milling procedure, grist:liquor ratio, time of mash stands, and grist modification level (well and poorly modified malt). During mashing β-glucan, free amino nitrogen (FAN) and extract contents were analysed as key indicators for cytolysis, proteolysis, and amylolysis, respectively. The malt modification was of major impact for the β-glucan release in contrast to a variation of milling procedure and of grist: liquor ratio. Extended stands lead to increased final values only for poorly modified malt. Similarly, FAN release was predetermined by malt modification while variation of milling and of grist: liquor ratio was not relevant in contrast to stand extension. None of the variations applied influenced extract yield as long as gelatinization temperature was reached. Greatest gains occurred around 57℃. In conclusion, wort quality is critically determined by malt modification. Mashing with well modified malt in combination with short stands should result in a mash of low β-glucan and sufficient FAN level without losing extract yield. However, for poorly modified malt the variation of mashing parameters has an impact on the key indicators in which cytolysis plays the dominating role.