Potatoes, water, sugar, salt, and sometimes
hops make a nutrient solution in which yeast
will grow. The hops help to eliminate un¬
desirable fermentation and also contribute to
the flavor. Salt, too, helps to control the
fermentation and improve the flavor. When
such a mixture is seeded with yeast (wild or
commercial), the yeast cells multiply, give
off carbon dioxide, and the batter becomes
foamy. This starter is used in making the
sponge (see page 314) for bread and rolls.
Then some of the sponge is saved, and used
to seed a starter for the next breadmaking.
Yeast starters must be stored in refrigerators,
and even then bacteria may develop which
give the bread a bad flavor. In this case, a
new starter has to be made with fresh yeast.
Favorable Conditions. Since yeast is a
living organism, the conditions under which
it will grow best are very important if it is to
be used successfully to leaven bread. First
of all, yeast must have food and, if the cells
are to multiply, this food must contain cer¬
tain essential nutrients. Yeasts lose their
activity if grown for too long a time in a pure
carbohydrate solution. They must also have
an adequate supply of water. They will
grow in a mixture of the consistency of
dough, but are more active if the mixture is
moist like a batter. On that account, bread
is frequently started in the form of a sponge
in order to accelerate the action of the yeast
cells. The activity of yeast cells is best when
the temperature is between 80° and 85° F.
Below 70° F. the action is slowed down, and
above 90° F. the growth of bacteria inhibits
[294]
the growth of the yeast cells. High tempera¬
tures kill the yeast cells.
The amount of yeast to use is determined,
in the home, by the length of time available
to make the bread or rolls. An average
amount is one cake of compressed yeast, or
its equivalent, to about a pound of flour.
Extra yeast speeds the fermentative changes.
Bakers commonly use from two to three per
cent yeast, although the amount may be
more or less than this.
Bacteria for Leavening. Other microor¬
ganisms which may be used for leavening
bread are certain harmless gas-forming bac¬
teria. These are used to leaven the so-called
salt-rising bread. The name of this bread has
come from the custom of adding salt to the
sponge, presumably to inhibit the growth of
certain undesirable organisms. The bacteria
leaven the bread by breaking down certain
of its ingredients, principally the sugars,
forming gaseous products, about two-thirds
hydrogen and one-third carbon dioxide.
Yeast produces no hydrogen.
These bacteria are found frequently in
cornmeal. They are peculiar in that they
lose their gas-producing power if kept in a
moist condition, and must be kept dry if they
are to survive for any length of time. These
bacteria are very resistant to heat because
they are in the spore state. This accounts
for their survival in the ordinary method of
making salt-rising bread in which scalded
milk is poured over the corn meal. They
grow best at a temperature some 20° to 25° F.
higher than yeast, the optimum temperature
being somewhere between 105° and 120° F.
Milk is an essential ingredient of the
bread made in this way, while the necessary
constituent of the milk seems to be the ca¬
sein. Casein and lactose (milk sugar) are
more effective than casein alone.
Page 269
Presented as published in 1935. Historical recipes may not meet modern food-safety standards. Cook from the modern interpretation, not the original instructions.
AI-modernized reading of the original text
Potatoes, water, sugar, salt, and sometimes hops make a nutrient solution in which yeast will grow. The hops help to eliminate un¬ desirable fermentation and also contribute to the flavor. Salt, too, helps to control the fermentation and improve the flavor. When such a mixture is seeded with yeast (wild or commercial), the yeast cells multiply, give off carbon dioxide, and the batter becomes foamy. This starter is used in making the sponge (see page 314) for bread and rolls. Then some of the sponge is saved, and used to seed a starter for the next breadmaking. Yeast starters must be stored in refrigerators, and even then bacteria may develop which give the bread a bad flavor. In this case, a new starter has to be made with fresh yeast.
Favorable Conditions. Since yeast is a living organism, the conditions under which it will grow best are very important if it is to be used successfully to leaven bread. First of all, yeast must have food and, if the cells are to multiply, this food must contain cer¬ tain essential nutrients. Yeasts lose their activity if grown for too long a time in a pure carbohydrate solution. They must also have an adequate supply of water. They will grow in a mixture of the consistency of dough, but are more active if the mixture is moist like a batter. On that account, bread is frequently started in the form of a sponge in order to accelerate the action of the yeast cells. The activity of yeast cells is best when the temperature is between 80° and 85° F. Below 70° F. the action is slowed down, and above 90° F. the growth of bacteria inhibits
[294]
the growth of the yeast cells. High tempera¬ tures kill the yeast cells.
The amount of yeast to use is determined, in the home, by the length of time available to make the bread or rolls. An average amount is one cake of compressed yeast, or its equivalent, to about a pound of flour. Extra yeast speeds the fermentative changes. Bakers commonly use from two to three per cent yeast, although the amount may be more or less than this.
Bacteria for Leavening. Other microor¬ ganisms which may be used for leavening bread are certain harmless gas-forming bac¬ teria. These are used to leaven the so-called salt-rising bread. The name of this bread has come from the custom of adding salt to the sponge, presumably to inhibit the growth of certain undesirable organisms. The bacteria leaven the bread by breaking down certain of its ingredients, principally the sugars, forming gaseous products, about two-thirds hydrogen and one-third carbon dioxide. Yeast produces no hydrogen.
These bacteria are found frequently in cornmeal. They are peculiar in that they lose their gas-producing power if kept in a moist condition, and must be kept dry if they are to survive for any length of time. These bacteria are very resistant to heat because they are in the spore state. This accounts for their survival in the ordinary method of making salt-rising bread in which scalded milk is poured over the corn meal. They grow best at a temperature some 20° to 25° F. higher than yeast, the optimum temperature being somewhere between 105° and 120° F.
Milk is an essential ingredient of the
bread made in this way, while the necessary constituent of the milk seems to be the ca¬ sein. Casein and lactose (milk sugar) are more effective than casein alone.