(c) Put 1 teaspoonful of the yeast mixture in a test tube, fill nearly
full of cold water and label it " c." Surround it with cracked ice or,
if the weather is cold, place it out of doors. After 15 minutes ex-
amine. Is there any change in the contents of the tube ? Why do
not the yeast plants grow ?
(d) Surround the tube marked u c" with lukewarm water and
stand in a warm place. After 15 minutes examine. Are the yeast
plants growing ? Does freezing kill yeast plants ?
(e) Mix \ cake yeast with a little lukewarm water. Stand in a
warm place and after 16 minutes examine. Will yeast grow in water
alone ?
(/) Mix \ cake yeast, 1 tablespoonful of sugar, and a little luke-
warm water. Set aside in a warm place so that the yeast plants may
grow. Then examine under the microscope. Are there any budding
228
YEAST; LOAF BREAD
229
yeast cells ? Make a drawing of the plants as they appear under the
microscope.
Draw at least two practical conclusions from these experiments as
to the use and care of yeast for bread making.
Properties of Yeast. — Yeast consists of a mass of micro-
scopic plants. (See Fig. 53.) When placed under proper
conditions these plants grow rapidly, and in so doing they
separate the sugar that exists in flour into carbon dioxide
and alcohol. The car-
bon dioxide lightens
dough. The alcohol
passes off as vapor in
baking.
Plants need moisture,
warmth, light, and the
food that is furnished
by the air and soil for
their growth. Yeast
plants require all of
these except light.
They are not green
plants, hence they need
no light. Moisture is
obtained from the
water, milk, or other liquids used in bread dough. Yeast
thrives at a temperature of 90° F. It is killed by a
temperature above 130° F. Hence the yeast is mixed with
lukewarm water. The other liquids that are added to it
are of the same temperature. Also, the dough is placed
in a warm place while it is rising, or while the yeast plants
are growing. The food required for the rapid growth of
the yeast is obtained from the protein and carbohydrates
in the flour.
Compressed yeast cakes which are wrapped in tinfoil and
received fresh at the market every day or two are the most
From Farmers Bulletin 389.
Fig. 53. — Growing yeast plants.
230 THE COOKING OP FOODS
satisfactory to use. This yeast must be fresh for successful
bread making. It is fresh when it is of a light color, is
free from dark streaks, and is crumbly in texture.
General Suggestions for Bread Making. — Use bread flour,
or a combination of bread flour with either whole wheat or
graham flour in making bread. Flour should be kept in a
dry place. It is well to warm flour for bread before using.
If milk is used, scald it to prevent it from souring.
Water should be boiled and then cooled. (See Why Foods
Spoil, p. 289.) Milk and water are both used lukewarm.
With 1 quart of liquid £ to 1 cake of yeast should be used.
The less quantity of yeast (£ cake) is used when the dough
is allowed to rise overnight. Mix 1 yeast cake in 1 cupful
of lukewarm water before adding the rest of the liquid.
It is well to make the dough into small loaves, and place
th^m in small pans, so that the bread will be baked through.
Loaves of bread should bake at least 1 hour at a tempera-
ture varying from 375° F. to 400° F. During the first 20
minutes they should rise but slightly and just begin to
brown ; during the second 20 minutes they should continue
to brown; during the last 20 minutes they should shrink
from the sides of the pan, while still continuing to brown.
To soften the crusty rub it with a bit of butter a few
minutes before taking from the oven and again after re-
moving from the oven. After baking, place the loaves of
bread on a bread cooler, or arrange them in such a way
that the air may reach them on all sides. When cool, place
in a covered tin box. ✪ Bread
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Presented as published in 1915. 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
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(c) Put 1 teaspoonful of the yeast mixture in a test tube, fill nearly
full of cold water and label it " c." Surround it with cracked ice or,
if the weather is cold, place it out of doors. After 15 minutes ex-
amine. Is there any change in the contents of the tube ? Why do
not the yeast plants grow ?
(d) Surround the tube marked u c" with lukewarm water and
stand in a warm place. After 15 minutes examine. Are the yeast
plants growing ? Does freezing kill yeast plants ?
(e) Mix \ cake yeast with a little lukewarm water. Stand in a
warm place and after 16 minutes examine. Will yeast grow in water
alone ?
(/) Mix \ cake yeast, 1 tablespoonful of sugar, and a little luke-
warm water. Set aside in a warm place so that the yeast plants may
grow. Then examine under the microscope. Are there any budding
228
YEAST; LOAF BREAD
229
yeast cells ? Make a drawing of the plants as they appear under the
microscope.
Draw at least two practical conclusions from these experiments as
to the use and care of yeast for bread making.
Properties of Yeast. — Yeast consists of a mass of micro-
scopic plants. (See Fig. 53.) When placed under proper
conditions these plants grow rapidly, and in so doing they
separate the sugar that exists in flour into carbon dioxide
and alcohol. The car-
bon dioxide lightens
dough. The alcohol
passes off as vapor in
baking.
Plants need moisture,
warmth, light, and the
food that is furnished
by the air and soil for
their growth. Yeast
plants require all of
these except light.
They are not green
plants, hence they need
no light. Moisture is
obtained from the
water, milk, or other liquids used in bread dough. Yeast
thrives at a temperature of 90° F. It is killed by a
temperature above 130° F. Hence the yeast is mixed with
lukewarm water. The other liquids that are added to it
are of the same temperature. Also, the dough is placed
in a warm place while it is rising, or while the yeast plants
are growing. The food required for the rapid growth of
the yeast is obtained from the protein and carbohydrates
in the flour.
Compressed yeast cakes which are wrapped in tinfoil and
received fresh at the market every day or two are the most
From Farmers Bulletin 389.
Fig. 53. — Growing yeast plants.
230 THE COOKING OP FOODS
satisfactory to use. This yeast must be fresh for successful
bread making. It is fresh when it is of a light color, is
free from dark streaks, and is crumbly in texture.
General Suggestions for Bread Making. — Use bread flour,
or a combination of bread flour with either whole wheat or
graham flour in making bread. Flour should be kept in a
dry place. It is well to warm flour for bread before using.
If milk is used, scald it to prevent it from souring.
Water should be boiled and then cooled. (See Why Foods
Spoil, p. 289.) Milk and water are both used lukewarm.
With 1 quart of liquid £ to 1 cake of yeast should be used.
The less quantity of yeast (£ cake) is used when the dough
is allowed to rise overnight. Mix 1 yeast cake in 1 cupful
of lukewarm water before adding the rest of the liquid.
It is well to make the dough into small loaves, and place
th^m in small pans, so that the bread will be baked through.
Loaves of bread should bake at least 1 hour at a tempera-
ture varying from 375° F. to 400° F. During the first 20
minutes they should rise but slightly and just begin to
brown ; during the second 20 minutes they should continue
to brown; during the last 20 minutes they should shrink
from the sides of the pan, while still continuing to brown.
To soften the crusty rub it with a bit of butter a few
minutes before taking from the oven and again after re-
moving from the oven. After baking, place the loaves of
bread on a bread cooler, or arrange them in such a way
that the air may reach them on all sides. When cool, place
in a covered tin box.