fire, and allowing free air circulation to carry
soot and other PAH-containing particles away.
Commercial smokers use air filters and
temperature control for these purposes.
Liquid Smoke
Liquid smoke is essentially smoke-flavored
water. Smoke consists of two phases:
microscopic droplets that make it visible as a
haze, and an invisible vapor. It turns out that
much of the flavor and preservative materials
are in the vapor, while the droplets are largely
aggregates of tars, resins, and heavier
phenolic materials, including the PAHs. PAHs
are largely insoluble in water, while most of
the flavor and preservative compounds do
dissolve to some extent. This difference
makes it possible to separate most of the
PAHs from the vapors and dissolve the vapors
in water. Cooks then use this liquid extract of
smoke to flavor foods. Toxicological studies