FoodNet

Experimental cookery

1932

Page 346

Presented as published in 1932. Historical recipes may not meet modern food-safety standards. Cook from the modern interpretation, not the original instructions.
Bread is a very complex substance. In addition to organic and inorganic materials it contains three substances that show colloidal behavior: the protein, the starch, and the cellulose. The amount of cellulose is quite small, so that it probably plays a very minor role in bread making. The part that different constituents of the flour play in the dough structure has been discussed in the preceding pages. Their part in bread making will not be repeated here, but the proportion of ingredients used, the temperature for handling the dough and for baking, the fermentation, and the importance of manipulation of the dough will be considered. Chemical and physical tests may be performed on flour and dough, but as yet the only final convincing proof of flour quality for making bread is the baking test. Temperature. Enzyme activity is very slow at low temperatures and the enzymes are destroyed at high temperatures. Thus for optimum enzyme activity and also for yeast growth in bread dough it is important to keep the dough at definite temperatures. PROPORTION OF INGREDIENTS USED IN BREAD 425 Fermentation is carried out over a wide range of temperature. The evidence indicates that a low temperature is more desirable from the stand- point of flavor and the development of acetylmethylcarbinol. But fermenta- tion is more rapid at higher temperatures. Temperatures from 26° to 32°C. (79° to 90°F.) are used. There is more danger at higher tempera- tures for growth of undesirable organisms which produce disagreeable flavors. Proportion of ingredients used in bread. The American Asso- ciation of Cereal Chemists (A.A.C.C.) appointed a committee, headed by Fitz, later by Blish and others, to find the proportion of ingredients used by members of the association in test bakes, and to formulate a stand- ard method of procedure and a definite formula for use by members of the association. Flour. It is customary in computing the percentage of ingredients used in bread to take flour as 100 and compute the proportion of the other ingredients in relation to it. Thus if 112 grams of flour are used and to this is added 65 per cent of water, 72.8 grams of water would be used. It requires about % pound of flour to produce a pound loaf of bread, though the exact amount depends largely upon the hydration capacity of the gluten. Yeast. Two types of commercial yeast may be purchased, the com- pressed and the dry. A cake of compressed yeast contains many yeast plants in an active state. When it is used the yeast plants multiply rapidly, pro- ducing a large quantity of carbon dioxide gas, and the fermentation takes place in a short time. In dry yeast the yeast is mixed with corn meal and dried. The yeast plants are not active, as they are in a dormant state and they are few in number. The yeast needs to be soaked for a short time in warm water and then made into a sponge to give time for the revival and growth of the yeast plants. Therefore it requires a longer fermentation period than com- pressed yeast.