Action of Yeast on Bread

Ingredients

• a little flour
• a little water
• a little compressed yeast

Method

1. 1

   Mix flour and water to form dough, divide into three lots.

2. 2

   Add yeast to A and B, let rise for 5-6 hours.

3. 3

   Bake C immediately.

4. 4

   Bake B after rising, and knead A before baking.

As published

This recipe was extracted from A laboratory manual of foods and cookery (1916) by Emma B. Matteson, page 78. The excerpt below is the record exactly as published.

a little water so as to make a slightly cloudy solution. Place a drop of the solution upon a micro- scope slide, cover with a cover glass, and examine first with a f-inch objective. Note that the water seems to be filled with very minute dots. Study with a higher power (^ in. objective). Examine the yeast cells, noting the shape and comparative size. 183. — Growing yeast. With a glass rod, remove a drop of the sediment from growing yeast prepared as in Expt. 180. Place the drop on a slide, cover with a cover glass, and study as in the previous case. Remove some of the yeast found floating on the surface and study in the same way. Note that the yeast cells are in groups. Make a sketch of several groups, showing buds of various sizes. Note any other differences you can see between this growing yeast and the compressed yeast cake. 184. - - Effect of boiling. Prepare two test tubes of molasses and water and inoculate each with a drop of yeast. Plug with cotton. Place one test tube in water and boil for ten minutes, and then leave both test tubes side by side in a warm place for two days, and deter- mine whether the boiling has been sufficient to kill the yeast. 185. - - Wild yeast. Prepare several test tubes of molasses and water as described and without plugging with cotton leave exposed in various places for two or three days. Determine by the appear- ance of bubbles whether fermentation occurs. If any change takes place in the liquids, examine with a microscope to determine whether yeasts have found entrance from the air or whether some other micro- organisms are growing in the solutions. Commonly, bacteria will be found more abundant than yeasts. 186. - - Effect of age on yeast. Obtain an old sample of dried yeast cake. Prepare two tubes of molasses and water and inocu- late one with a small quantity of the old yeast cake and two others with a similar quantity of a fresh cake. Set aside in a warm place and determine in which fermentation starts sooner, and in which it 1 84 LABORATORY MANUAL OF FOODS AND COOKERY is the more vigorous. Examine with a microscope after fermenta- tion begins, to see if either contains other organisms besides yeast. 187. - - Action of yeast on bread. Mix up a little flour and water to about the consistency of dough for bread making and divide into three lots, A, B, and C. Into A and B place a little compressed yeast

Cook this with the app: pantry check, scaling, and the assistant.