inutes, filter and then
titrate 50 cc. of the filtrate against standard KOH solution, using
phenolphthalein as indicator, 1 cc. of the alkali equals 0.009 gms.
lactic acid. Calculate the per cent of acid present.

1. How may the acidity of a flour be determined? 2. The acidity is
expressed in percentage amounts of what acid? 3. What per cent of
acidity is found in normal flours? 4. What does a high acidity of a
flour indicate?

Experiment No. 27

Moist and Dry Gluten

Weigh 30 gms. of flour into a porcelain dish. Make the flour into a
stiff dough. After 30 minutes obtain the gluten by washing, being
careful to remove all the starch and prevent any losses. Squeeze the
water from the gluten as thoroughly as possible. Weigh the moist gluten
and calculate the per cent. Dry the gluten in the water oven and
calculate the per cent of dry gluten.

Experiment No. 28

Gliadin from Flour

Place in a flask 10 gms. of flour, 30 cc. of alcohol, and 20 cc. of
water. Cork the flask and shake, and after a few minutes shake again.
Allow the alcohol to act on the flour for an hour, or until the next
day. Then filter off the alcohol solution and evaporate the filtrate to
dryness over the water bath. Examine the residue; to a portion add a
little water; burn a small portion and observe odor.

1. Describe the appearance of the gliadin. 2. What was the result when
water was added? 3. When burned, what was the odor of the gliadin, and
what does this indicate? 4. What is gliadin?

Experiment No. 29

Bread-making Test

Make a "sponge" by mixing together:

12 gm. sugar,
12 gm. yeast (compressed),
4 gm. salt,
175 cc. water (temp. 32 deg. C.).

Let stand 1/2 hour at a temperature of 30 deg. C. In a large bowl, mix
with a knife or spatula 7.7 gms. of lard with 248.6 gms. of flour. Then
add 160 cc. of the "sponge," or as much as is needed to make a good stiff
dough, and mix thoroughly, using the spatula. With some flours as small
a quantity as 150 cc. of sponge may be used. If more moisture is
necessary, add H_{2}O. Keep at temperature of 30 deg. C. Allow the dough
to stand 50 minutes to first pulling, 40 minutes to second pulling, and
30 to 50 minutes to the pan. Let it rise to top of pan and then bake for
1/2 hour in an oven at a temperature of 180 deg. C. One loaf of bread is
made of patent flour of known quality as a standard for comparison, and
other loaves of the flours to be tested. Compare the loaves as to si