The control of volatile ester synthesis during the fermentation of wort of high specific gravity

TLDR: In this paper, the authors studied the effects of fermenting wort of unusually high specific gravity, followed by dilution with water to give beer of normal original gravity, but matching of flavors requires control of the level of flavour determinants.

Abstract: Some effects have been studied of fermenting wort of unusually high specific gravity, followed by dilution with water to give beer of normal original gravity. This procedure permits increased overall rates of beer production, but matching of flavours requires control of the level of flavour determinants. If not controlled, the concentration of volatile esters may be disproportionately increased so that, after dilution, beer flavour is markedly different. Higher alcohol production is not affected in this way. The concentration of esters can be adjusted to appropriate levels by increasing the production of yeast mass during fermentation. Unsaturated fatty acids, which increase yeast dry matter production without altering the rate of fermentation, are particularly effective in reducing the extent of ester synthesis.