THE EFFECT OF WORT BOIL TIME AND TRUB ON BARLEY MALT FERMENTABILITY THROUGH THE MINIATURE FERMENTATION METHOD

Abstract

The basic aim of barley malt breeders and maltsters is to produce malt with optimum fermentability levels. The purpose of this research was to understand and evaluate the effect of wort boiling and autoclaving at varying time periods (30, 45, 60, 90, and 120 min) on malt fermentability. The effect of trub content was also analyzed. Small-scale fermentations were carried out using a ‘Control malt’ and a standard SMA yeast strain. The Apparent Degree of Fermentability (ADF), Turbidity (absorbance at 600nm), and Density (oPlato) were measured at specific time intervals over three day fermentation period and non-linearly modeled. From the results obtained, we suggest that heat treating wort with or without trub, (at 100°C, 121.1°C) for a range of times results in significant decline in the ADF (p<0.05). Free amino nitrogen levels of wort declined significantly with respect to both increase in wort boiling temperature and intervals (p<0.001).