WORT-BOILING IN RELATION TO BEER QUALITY

Abstract

Comparisons of beers from worts mashed with pale ale malts (nitrogen 1·3%) at 150°F. (65·5°C.) and boiled for 1/2, 1 and 2 hr. show that increase in boiling time leads to slightly increased hop-utilization, decreased head-retention, improved non-biological stability and slight differences in flavour. Findings were very similar when the mashing temperature was either 145°F. (63°C.) or 155°F. (68°C.) except that, in the latter case, no difference in flavour was detectable between beers from long and short boiled worts. Stirring can replace vigorous boiling to secure normal hop-utilization and shelf-life but simmered worts give beers of characteristic flavour probably as a result of enhanced contents of hop oil. Use of a lightly kilned malt of high nitrogen content (1·8%) produced a characteristically different flavour from that obtained with pale-ale malt and reduced the utilization of hop substances by provoking a greater loss of this material during fermentation.