KefirBecause milk contains an appreciable
amount of the sugar lactose, it can be
fermented like grape juice and other sugary
fluids into an alcoholic liquid. This
fermentation requires unusual lactose-
fermenting yeasts (species of
Saccharomyces, Torula, Candida, and
Kluyveromyces). For thousands of years,
the nomads of central Asia have made
koumiss from mare’s milk, which is
especially rich in lactose, and this tart,
effervescent drink, with 1–2% alcohol and
0.5–1% acid, remains very popular there
and in Russia. Other European and
Scandinavian peoples have made alcoholic
products from other milks, as well as
sparkling “wine” from whey.
Another remarkable fermented milk
little known in the West is kefir, which is
most popular in the Caucasus and may well
have originated there. Unlike other