Abstract

RIVERA JIMENEZ, María Teresa et al. Mashing and fermentation conditions that increase ethanol content in fermented wort for single malt whisky. Biotecnia [online]. 2022, vol.24, n.1, pp.133-141.  Epub June 13, 2022. ISSN 1665-1456.  https://doi.org/10.18633/biotecnia.v24i1.1576.

Ethanol content in fermented wort is the most important parameter for whisky production, in terms of volume of distillate per unit of malt. Ethanol biosynthesis during wort fermentation depends on many factors, however, the initial concentration of fermentable carbohydrates significantly affects the final ethanol content in fermented wort. The objective of this study was to evaluate the effect of different mashing and fermentation conditions on ethanol content in fermented wort, and to determine the conditions that better contribute to the increase of this compound. It was observed that an isothermal mashing of 65 ºC for 3 h, with a 1:3 grist:water ratio, results in worts with high fermentable carbohydrates content. In addition, it was determined that the higher ethanol yield is attained with closed fermenters at 20 ºC and 12.5 ºP worts. These conditions result in a conversion efficiency of 0.34 g of ethanol/g of soluble solids, in fermented worts with reduced amounts of methanol and glycerol.

Keywords : whisky; malt; mashing; fermentation; ethanol yield.