2009_Book_FoodChemistry

934 20 Alcoholic Beverages
In the production of Scotch grain whiskey the saccharified
starch is distilled in continuous column
stills. The character of the distillate is neutral,
with less aroma than malt whiskey. In both Scotch
whiskey processes, the distillates, with about
63% by volume ethanol, have to be stored/aged
in order to develop their full aroma. This is
best achieved by aging in old sherry casks or in
charred casks. At the end of processing, the alcohol
content is reduced to a drinkable level, about
43% by volume. Depending on the desired flavor
or current preferences, the malt whiskey might be
blended with grain whiskey (“blended whiskey”).
American whiskey is made from corn, rye or
wheat by saccharification with malt enzymes, fermentation
of the wort, followed by doubledistillation
in column stills and aging, usually in
charred oakwood casks. The corn distillate content
of bourbon whiskey is at least 51% by volume
and that of corn whiskey is at least 80% by
Table 20.28. Odorants of whisky
Aroma substance
Malt whisky a
Concentration (mg/l)
Bourbon whisky b
Ethanol 316,000 316,000
2-Methoxyphenol 0.025 0.056
5-Methyl-2-methoxyphenol 0.0019 0.0011
4-Methyl-2-methoxyphenol 0.01 0.016
4-Ethyl-2-methoxyphenol 0.017 0.059
2-Methylphenol 0.034 0.003
4-Methylphenol 0.017 0.008
3-Methylphenol 0.008 0.004
4-Ethylphenol 0.016 0.166
3-Ethylphenol 0.0033 n.d.
Eugenol 0.027 0.24
3-Methylbutanol 568.1 1062.1
2-Methylbutanol 194.2 423.8
2-Phenylethanol 11.2 13.87
Ethylbutanoate 0.76 0.55
Ethylhexanoate 2.07 1.99
Ethyloctanoate 12.3 8.35
Ethyl-2-methylpropanoate 0.52 0.13
Ethyl-3-methylbutanoate 0.21 0.052
(S)-Ethyl-2-methylbutanoate 0.092 0.030
(S)-Ethyl-2-hydroxy-3-methylbutanoate 0.005 0.003
(2S,3S)-Ethyl-2-hydroxy-3-methylpentanoate 0.004 0.003
3-Methylbutylacetate 4.02 2.59
2-Phenylethylacetate 4.10 1.94
Methylpropanal 1.74 0.23
3-Methylbutanal 0.65 0.34
Vanillin 0.68 2.13
(3S,4S)-cis-Whisky lactone 0.39 2.49
(3S,4R)-trans-Whisky lactone 0.07 0.34
γ-Nonalactone 0.11 0.12
γ-Decalactone 0.010 0.002
2,3-Butandione 0.39 0.033
(E)-β-Damascenone 0.024 0.011
(E)-2-Nonenal 0.024 0.009
(E,E)-2,4-Decadienal 0.006 0.039
1,1-Diethoxyethane 21.86 15.33
a Single malt whisky from Scotland, stored for 8 years in an oak cask.
b American Kentucky straight bourbon whisky, stored for at least 3 years in a charred oak cask.