Use of freeze concentration for preparing malt liqueurs.

Patino, H., Knudsen, F.B., Gress, H.S. and Heard, G.E.

Abstract
Liqueurs are normally based on distilled spirits, but the products described in this paper are prepared by brewing a beer (of normal composition except for being very lightly hopped), concentrating it by freezing its water content and filtering out a sufficient proportion of the ice to increase its alcohol concentration to about 17% by weight, and adding various flavourings. The volatile compounds composition, aroma and flavour of some of the products obtained are compared with conventional liqueurs ("cream of coffee schnapps" and "amaretto") and brandy. Considerable variation in the final product can be brought about by altering the mash recipe, the brewing process, the degree of concentration after freezing, the type and quantity of flavouring used, or any combination of these.
Keywords : beer brewing concentration flavour freezing liqueur production