formation of air cells through the medium of
acetous fermentation, as in yeast bread; by the mechanical introduction
of carbonic acid gas, as in aerated bread; by the mixture with the flour
of a gas-generating compound, which needs only the contact of moisture
to put it in active operation; and by the beating into the dough of
atmospheric air. No organic change in the elements of the flour is
necessary, like that produced by the partial decomposition of some of
its properties, in bread raised with yeast; so long as proper surface is
obtained for the action of the gastric juices, the purpose of raising is
accomplished. Bread raised without fermentation can be made from the
following receipt, and there is no question of its healthfulness.

254. =Aerated Homemade Bread.=--Mix flour and water together to the
consistency of a thick batter; then beat it until fine bubbles of air
thoroughly permeate it; for small biscuit, pour it into patty pans, and
bake in a good brisk oven; for bread in loaves more flour is thoroughly
kneaded in with the hands, until the dough is full of air-bubbles, and
then baked at once, without being allowed to stand.

When bread is to be raised by the acetous fermentation of yeast, the
sponge should be maintained at a temperature of 89 deg. Fahr. until it is
sufficiently light, and the baking should be accomplished at a heat of
over 320 deg. When yeast is too bitter from the excess of hops, mix plenty
of water with it, and let it stand for some hours; then throw the water
off, and use the settlings. When yeast has soured it may be restored by
adding to it a little carbonate of soda or ammonia. When dough has
soured, the acidity can be corrected by the use of a little carbonate of
soda or ammonia. If the sponge of "raised bread" be allowed to overwork
itself it will sour from excessive fermentation, and if the temperature
be permitted to fall, and the dough to cool, it will be heavy. Thorough
kneading renders yeast-bread white and fine, but is unnecessary in bread
made with baking-powder. Great care should be taken in the preparation
of yeast for leavened bread, as the chemical decomposition inseparable
from its use is largely increased by any impurity or undue fermentation.
Experience and judgment are necessary to the uniform production of good
bread; and those are gained only by repeated trials. We subjoin one of
the best receipts which we have been able to procure, for making yeast.

255. =Homebrewe