es dates back to the very dawn of history,
and the authentic record of raised or leavened bread is but little
more than 3000 years old.

214. The Bread of Antiquity. The original method of bread making and
the method employed by savage tribes of to-day is to mix crushed grain
and water until a paste is formed, and then to bake this over a camp
fire. The result is a hard compact substance known as unleavened
bread. A considerable improvement over this tasteless mass is
self-raised bread. If dough is left standing in a warm place a number
of hours, it swells up with gas and becomes porous, and when baked, is
less compact and hard than the savage bread. Exposure to air and
warmth brings about changes in dough as well as in fruit juices, and
alters the character of the dough and the bread made from it. Bread
made in this way would not seem palatable to civilized man of the
present day, accustomed, as he is, to delicious bread made light and
porous by yeast; but to the ancients, the least softening and
lightening was welcome, and self-fermented bread, therefore,
supplanted the original unleavened bread.

Soon it was discovered that a pinch of this fermented dough acted as a
starter on a fresh batch of dough. Hence, a little of the fermented
dough was carefully saved from a batch, and when the next bread was
made, the fermented dough, or leaven, was worked into the fresh dough
and served to raise the mass more quickly and effectively than mere
exposure to air and warmth could do in the same length of time. This
use of leaven for raising bread has been practiced for ages.

Grape juice mixed with millet ferments quickly and strongly, and the
Romans learned to use this mixture for bread raising, kneading a very
small amount of it through the dough.

215. The Cause of Fermentation. Although alcoholic fermentation, and
the fermentation which goes on in raising dough, were known and
utilized for many years, the cause of the phenomenon was a sealed book
until the nineteenth century. About that time it was discovered,
through the use of the microscope, that fermenting liquids contain an
army of minute plant organisms which not only live there, but which
actually grow and multiply within the liquid. For growth and
multiplication, food is necessary, and this the tiny plants get in
abundance from the fruit juices; they feed upon the sugary matter and
as they feed, they ferment it, changing it into carbon dioxide and
alcohol. The ca