Perception of whisky flavour reference compounds by Scottish distillers

A set of 16 compounds was selected from the literature as potential flavour standards for whisky profiling: acetic acid (sour), diacetyl (buttery), dimethyl tri sulphide (sulphury), ethyl hexanoate (fruity-appley), ethyl laurate (soapy), furfural (grainy), geraniol (floral), guaimcol (smoky), hexanal (grassy), iso-amyl acetate (fruity-banana), iso-valeric acid (sweaty), maltol (sweet), phenyl ethanol (floral), vanillin (vanilla), 4-vinyl guaiacol (spicy) and whisky lactone (coconut). Each compound, at 90% recognition threshold concentration, that at which 90% assessors recognise the flavour character, was added to 3 year old grain whisky diluted to 23% v/v. The solutions were assessed by 72 distilling professionals (blenders, quality control and technical functions) and flavour attributes suggested without, and subsequently with, a prompt list were recorded. Descriptors with a frequency of >10% were examined. Only limited agreement was found across the industry. Agreement on reference standards and commonality in procedures for training of both blenders and sensory assessors would be of benefit to the whisky industries.