A fine white powder that forms on the wrapper of the
cigar caused by the
oils that exude from the
tobacco. It can be gently brushed off with a small
camel hair brush, though there is no need to do this. Bloom indicates the cigar is alive,
maturing as it should inside a well maintained
humidor. Bloom should not be confused with mold.
Mold is a bluish-green and stains the wrapper. Mold usually indicates a humidor is too warm or has
excessive levels of
humidity.
From the cigar glossary at www.bloomberg.com