Whisky Wood spirit

The application of active packaging is certainly not new. The most likely, oldest application of active packaging is the use of wood barrels for the storage and maturation of wine, whisky and other alcoholic stimulants. If the wooden barrels were used initially to store spirits, it was discovered a long time ago that due to the release and absorption of substances, the sensory properties of the stimulants were improved. 

The production of cheap and palatable Scotch whiskies involves a different set of considerations. It is necessary for pot still spirits to mature in wood in order that they should acquire a pleasant flavor. Patent still whiskies, on the other hand, although they are improved by aging in wood, change to a less extent and mature much more quickly. It is stated that by blending immature pot still with patent still whiskey the pungent, unpleasant taste of the former is attenuated or toned down and that the mixture then becomes a palatable and not unwholesome spirit. Such a mixture, if stored in wood, would mature in a shorter time than would the pot still whiskey alone. 

Whiskey is prepared from fermented grain. The malt which is used, is dried over an open fire, and, consequently, acquires a characteristic flavor, which is transmitted to the whisky. After fermentation, the product is distilled from a still of copper, and the distillate condensed in a worm. Redistillation yields a spirit which is diluted with enough water to make a solution which contains 50 to 58 per cent alcohol. The quantity of alcohol is usually stated in the United States in the per cent alcohol by volume as taxes are levied on that basis. The percentages given here refer to the volume standard. The crude whisky is stored in barrels of wood and allowed to age until the flavor of the fusel oil disappears. 

Aliphatic lactones are important as aroma components in foods and flavors. Among them, y-lactones preferentially occur in plants and J-lactones are mainly found in animal products. The details on naturally-occurring lactones as aroma components are described in the literature (87). It is interesting that quercus lac-tone-a (1) and -b (2), two diastereomeric branched nonlactones, have been detected as ingredients in aged whiskeys (88, 134). These lactones were isolated from woods of some Quercus species which are widely used to make barrels for aging spirits such as whisky and brandy (72, 73). 

Other important odorous components of foods are fragrant lactones derived from branched aliphatic hydroxycarboxyhc acids. The trivial names are normally preferred. An important component of the aroma of wines and spirits aged in oak barrels (such as whisky) is the so-called whisky lactone, 5-butyl-4-methyl-4,5-dihydro-3H-furan-2-one (3-methyloctano-4-lactone, 3-methyl-4-octanolide or 4-butyl-3-methylbutyrolactone), also known as cognac or oak lactone, which can exist in four stereoisomers, ofwhich the (3S,4S)-isomer (8-106) predominates. In brandy, for example, the content of the (Z)-isomers, (3R,4R)- and (3S,4S)-isomers, that have a desirable flavour, ranges between 30 and 247 xg/l. The (E)-isomers, (3S,4R)- and (3E,4S)-isomers, are found at a concentration of 115-736 p.g/1. The precursor of the (3S,4S)-isomer in oak wood... 

Ellagotannins occur as components of commercial tannic acid, various extracts and infusions (e.g. teas from medicinal herbs and bark of trees) and are also natural constituents of some alcoholic beverages matured in oak barrels, for example high quality wines and spirits, such as cognac, brandy, whisky, bourbon and rum. All components extracted from the wood are then degraded to some extent, which gives rise to various phenohc compounds that have a role to play in the flavour-active components of the alcohohc beverage (Table 8.44). 

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