Whisky or Whiskey

Composition.

As already indicated the proportion of second ary constituents is higher in the pot still than in the patent still spirits. This is particularly the case with the "higher alcohols" and "furfural." The latter is almost invariably absent from the patent still prod uct immediately after distillation, although a trace may be found after long storage. The proportion of these two ingredients may therefore be accepted as a basis for differentiation between the two types of spirit. The age of the spirit is an important factor.

Maturation.

The alterations in the character of a spirit dur ing storage may be attributed to (a) the type of cask and method of storage, and (b) the interaction of various ingredients.

(a) The secondary constituents most affected by ageing—particularly in the pot still whiskies—are the volatile acids and the aldehydes. Pot still whisky is usually stored in sherry casks or in well seasoned casks which have formerly contained spirit. The wine or spirit in the cask slowly diffuses into the wood, the ethyl alcohol passing through and evaporating, whilst such ingredients as higher alcohols and esters are held. When the cask is emptied the alcohol remaining absorbed is transformed by oxidation into acids, aldehydes and esters. On the cask being refilled with the new spirit the constituents thus formed are partially extracted, particularly during the earlier period of storage. Whisky stored in bottle and commercial spirit of high strength stored in metal containers are not subject to the same alterations.

(b) The reactions which take place within the spirit are much more complex and difficult of explanation. They may in part be attributed to the unintentional presence of small quantities of impurities derived from external sources during the process of manufacture and dependent upon the varying conditions. Thus Thorpe found pyridine bases, ally!

alcohol and ally! aldehyde probably derived from the peat, and acrolein due either to the oil extracted from the grain or to the soap which is occasionally added to the contents of the still to prevent frothing. In new pot still spirit Schidrowitz found evidence of the presence of pyrrole and phenolic and sulphurous bodies all of which would interact with the natural ingredients of the spirit to produce substances which would not otherwise be present.

Artificial maturing of spirit is sometimes attempted and various methods have been adopted, the object being to reduce the pro portion of secondary ingredients, particularly aldehydes, and thus to eliminate the harshness of new spirit.

Blending.

During the past century the practice of blending has gradually extended, particularly in Scotland and now very little "self-whisky" or unblended whisky is sold. It serves two purposes.

(I) To produce a brand of standard flavour. This is particularly the case in the products of the pot still.

(2) To meet the popular demand for a cheap mild flavoured spirit.

The best brands usually consist of approximately half High land and Lowland malts, a small quantity of Islay and the re mainder patent still spirit. (F. G. H.' T. ; X. ) Consumption in the United Kingdom.—During the years 1936-38 the consumption of British-made spirits averaged about 8,000,000 proof gallons, a marked decrease from the 10,712,002 proof gallons of 1926-27, the 17,825,871 proof gallons of 1919-20, and the 26,794,739 proof gallons of 1913-14.

In 1938 the United Kingdom imported approximately 1,231,000 proof gallons of spirits and in the first nine months of that year distilled 61,515,688 proof gallons, of which 7,301,286 were for export.