Peat
Densely compressed, decayed vegetation cut from bogs and dried, then used in the
malting process as a smoke-producing fuel that both dries the
barley and imparts a distinct flavor. Peat smoke is used in the production of certain Scotch whiskies, including many from
Islay. It is used in the production of some whiskies from other countries as well, including Ireland, India, Japan, and the United States. Levels of "peatiness" in whisky are measured in
phenol parts per million, or
PPM.