Spirits and Liqueurs

Rectified spirit is also used for the manufacture of liqueurs, by addition of various substances, such as natural or artificial essences, sugars, bitter principles, etc. 

The tests to be made on spirits and liqueurs include a certain number which are common to all these products, such as determinations of the alcoholic strength, extract and ash, and tests for impurities and denaturing agents other investigations are made only with certain products, examples of these being the examination of kirschwasser for hydrocyanic acid, the determination of sugars in liqueurs, etc. The former are treated under General Methods and the latter in the Special Part. 

Sampling.—Whatever the product to be examined, sampling is of the utmost importance. The sample should be taken from the vessels or casks after the mass has been well mixed or it should be drawn in portions from different levels by means of special siphons.1 If the product is distributed between several casks, quantities from each proportional to the contents should be mixed. It is, however, always preferable, especially when there is no absolute certainty as to the identity of the products in the different vessels, to take a separate sample from each and to indicate the quantity represented by each sample. 

The amount of liquid necessary for analysis varies according to tl e determinations required in general 0-5-1 litre is sufficient. Each sample should be stored in a clean, dry bottle, which is filled and then tightly closed. 

1 This is absolutely necessary, especially when the spirits are contained in large vessels holding many hectolitres, since layers form which may vary in specific gravity and hence in alcoholic strength. 

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Aroma compounds in distilled spirits and liqueurs, their levels, odour attributes, and thresholds are most important for quality and authenticity. Using gas chromatography and mass spectrometry, especially the composition of volatile aroma compounds in distilled spirits has been widely investigated [4-8]. By direct injection of an alcoholic distillate it is possible to determine more than 50 components within levels between 0.1 and 1,000 mg L b special methods of extraction can be used to increase this number up to more than 1,000 volatile substances [6]. However, sensory analysis is still indispensable to describe and evaluate spirit drinks. 

Artificial Sweetening Substances.—These are detected in a moderately concentrated solution of the substance by the methods given for liqueurs (see Spirits and Liqueurs). 

These include mainly crystallised fruits, preserved fruits, jams, chocolates, sweetmeats, biscuits, effervescent citrate of magnesia, honey, condensed milk, liqueurs and sweet wines. Certain of these products are dealt with in other places, condensed milk, liqueurs and sweet wines, for instance, in the chapters dealing respectively with milk, spirits and liqueurs, and wines. The others are treated below, special attention being paid to the determination of the sugars. 

P.V Price, Penguin Book of Spirits and Liqueurs, Handbook Series. Penguin Books, New York, 1981. 

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