The influence of malt and wort processing on spirit character: the lost styles of Scotch malt whisky

Over the last 50 years there has been considerable analytical research on the malt parameters which govern the flavour and aroma, i.e. the ‘character’, of Scotch malt whisky. This has led to a standard format, the Flavour Wheel, to describe the attributes of any malt spirit and to relate them to a common group of malt parameters. What has not been well documented in the same period are the changes in malt processing technology which have led to a gradual but significant change in the concentrations of reference compounds used in the Flavour Wheel relating to sulphury, nutty/burnt/smoky, peaty and fruity/estery characters. This review covers the most significant of these changes, which have become common practice across the industry, and specifically demonstrates how different malting barley varieties, malt kilning and peating, wort recovery, yeast management, and wash still heating have all contributed to the loss of some styles of malt whisky. © 2019 The Institute of Brewing & Distilling