This section is from the book "Beverages And Their Adulteration Origin, Composition, Manufacture, Natural, Artificial, Fermented, Distilled, Alkaloidal And Fruit Juices", by Harvey W. Wiley. Also available from Amazon: Beverages And Their Adulteration.
The kind of alcohol used in the manufacture of liqueurs and cordials is not always the same. Usually pure neutral spirit or cologne spirit is selected for this purpose. In the United States spirit of this kind, as has already been stated, is made from Indian corn; in Germany it is made from the potato; in France it may be made from the grape or from the sugar beet; in Spain it may be made from the grape or sometimes from the sweet potato. If neutral spirit is not used then the next best thing to employ, in the way of spirit, is brandy. Neutral spirit, being very much cheaper is usually preferred for this purpose. It is highly important that this neutral spirit be as pure as technical skill can make it, since it is not aged in wood before it is employed in the making of this liqueur. It should be as nearly pure ethyl alcohol as can be secured.
 
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