water to the desired final alcohol content, in
the neighborhood of 40%. Small quantities of
other ingredients may be added to fine-tune
the flavor and color; these include caramel
coloring, sugar, a water extract made by
boiling wood chips (the boisé of Cognac and
Armagnac), and wine or sherry (blended U.S.
and Canadian whiskeys).
Chill-Filtering Many spirits are chill-filtered:
chilled to below the freezing point of water,
and then filtered to remove the cloudy
material that forms. The substances that form
the cloud are poorly soluble fusel oils and
volatile fatty acids from the original spirits,
and a variety of similar substances extracted
from the barrel. Their removal prevents the
spirits from clouding when the drinker chills
them or dilutes them with water, but it also
removes some flavor and body, so some
producers choose not to chill-filter. Clouding
does not occur in spirits with more than about