Materials

1 cup of flour, a 10-inch square of cheesecloth, a piece of string, a pan or tin or granite plate.

Method

Tie the flour in the cheesecloth, and wash it, preferably under the faucet, until the starch is washed out. Remove the gluten, stretch and knead into a ball. Place the ball on a pan in the oven. Note results. Note temperature of oven, if possible. B. Experiments with yeast.

1. Materials. (a) 1 cake of yeast dissolved in 1/3 of a cupful of lukewarm water with water added to make 1/2 cupful. (b) 1/4 cup water and | cup flour stirred together + 1 tablespoonful of molasses. Divide this mixture into three parts.

Method

Add 2 tablespoonfuls of (a) to each of two thirds of (6). Put remaining portion of (a) into a saucepan and bring it to the boiling point and then add it to the third part of (b). Number these bowls 1, 2, 3.

(1) Surround bowl No. 1 with lukewarm water and keep the water at this temperature by adding warmer water from time to time. Note result.

(2) Surround bowl No. 2 with cracked ice and salt. Note result.

(3) Surround bowl No. 3 with lukewarm water as in No. 1. Note result.

(4) Before the end of the hour remove bowl No. 2 from the ice water and surround it with water at 100° F. and watch results.

State conclusions as to effect of temperature upon the growth of the yeast cell.

2. Materials

Materials. 1 yeast cake dissolved in 1/2 cup of water 80° F. + 1 tablespoonful molasses. Limewater. 4 small wide-mouthed bottles, or test tubes, 4 saucers or beakers.

Method

Fill the small bottle, cover with a saucer and invert; or the same with the test tubes. Keep the bottles at a temperature of 80° F. until they are emptied. Test for carbon dioxide with a match, and with limewater.

I. Plain bread. - You should be able to make your own recipe for plain bread from the foregoing pages. Write this out in detail.