Origins of the perceived nutty character of new-make malt whisky spirit

New-make malt spirits were sourced from 35 individual Scotch Whisky distilleries and their sensory characteristics rated by a trained panel using descriptive analysis. Selected samples (either high or low in perceived nutty character) were analysed using gas chromatography–olfactometry to identify regions of the resulting chromatograms, and the underlying compounds that were associated with nutty, nutty–cereal or nutty–oily characters. The concentrations of 19 ‘candidate’ nutty compounds were subsequently analysed in all 35 spirit samples and their analytical concentrations modelled as factors against sensory panel scores for ‘nutty’, ‘oily’, ‘feinty’ and ‘cereal’ characters. The model for spirit nutty character included positive contributions from 2,5-dimethylpyrazine, 2-furanmethanol and ethyl benzoate and a negative correlation with γ-nonalactone concentration. Analysis of a spirit sample manufactured using chocolate malt, and noted for its nutty character, confirmed the likely significance of pyrazine compounds to spirit nuttiness. Furfural concentration was positively correlated with perceived cereal, oily and feinty characters. Some co-correlation was evident between the four sensory characters, which may indicate that they have similar origins. Alternatively they may not be clearly defined from one another from a sensory perspective, or there might be complex interactions with other spirit flavours that mask or enhance these four attributes in a similar way. This highlights the likely complexity of nutty (and other Maillard related) characters in malt spirit.