ferment fails, in which case an artificial ferment is prepared.

One pint of ferment is allowed to every five pints of fresh milk in the
cask or churn, and the whole is beaten with the dasher for about an
hour, when it is set aside in a temperature of +18 degrees to +26
degrees Reaumur. When, at the expiration of a few hours, the milk turns
sour and begins to ferment vigorously, it is beaten again several times
for about fifteen minutes, with intervals, with a dasher which
terminates in a perforated disk, after which it is left undisturbed for
several hours at the same temperature as before, until the liquid begins
to exhale an odor of spirits of wine. The delicate offices of our Tatar
beauty, the taster, come in at this point to determine how much freshly
drawn and cooled milk is to be added in order rightly to temper the sour
taste. After standing over night it is ready for use, and is put up in
seltzer or champagne bottles, and kept at a temperature of +8 degrees to
+12 degrees Reaumur. At a lower temperature vinegar fermentation sets in
and spoils the kumys, while too high a temperature brings about equally
disastrous results of another sort. Kumys has a different chemical
composition according to whether it has stood only a few hours or
several days, and consequently its action differs, also.

The weak kumys is ready for use at the expiration of six hours after
fermentation has been excited in the mare's milk, and must be put into
the strongest bottles. The medium quality is obtained after from twelve
to fourteen hours of fermentation, and, if well corked, will keep two or
three days in a cool atmosphere. The third and strongest quality is the
product of diligent daily churning during twenty-four to thirty-six
hours, and is thinner than the medium quality, even watery. When
bottled, it soon separates into three layers, with the fatty particles
on top, the whey in the middle, and the casein at the bottom. Strong