Experimental cookery

In addition to the dry and the compressed yeast, two other types of yeast are used by housewives, chiefly farm women, where yeast cakes or bread cannot be delivered every day. A liquid yeast may be used and also a starter. The starter is a portion of the sponge that is saved to start the fermentation of the next baking of bread. Since the sponge or dough contains numerous yeast plants it is used instead of yeast cakes for the adding of yeast plants to the dough. To this starter sugar is added for food for the growth of the yeast during storage. After yeast is added to the bread a period of time elapses before the bread is baked. This period, the length of which depends upon the propor- tion of ingredients and the kind of yeast used, is called the fermentation period. Bakers call it ''proofing" and housewives "rising." Amount of yeast. The amount of yeast used in bread may vary in wide proportions. Fitz found that as a general rule bakers use 2 to 3 per cent of 426 FLOUR AND BREAD yeast, although the amount varies from 1 to 5.88 per cent. For home or school the amount may be increased according to the length of time allowed for the fermentation period. The following table taken from the pamphlet ''Baking Better Bread" by the Washburn Crosby Company gives the amount of yeast to use for different periods of fermentation for straight-dough process. TABLE 47 Amount of yeast Period of fermentation Temperature 1 cake of yeast to \}i cups liquid .... 4 hours 2 hours 1st rising 1 hour 2nd rising 1 hour in pans 80 2 cakes of yeast to 1^ cups liquid . . . vS hours V/2 hours 1st rising 45 minutes 2nd rising 45 minutes in pans 80 3 cakes of yeast to \}4 cups liquid . . . 2 hours 10 minutes 1 hour 1st rising 15 minutes 2nd rising 35 minutes in pans 80 4 cakes of yeast to 1>^ cups liquid . . . 1 hour 25 minutes 1st rising 5 minutes 2nd rising 30 minutes in pans 80 Water. Milk may be substituted for water in bread. It is usually scalded to destroy any bacteria or organisms that may produce undesirable flavors or be detrimental to yeast action. Since milk contains about 12 to 14 per cent solids, a larger proportion of it is added than of water. Water in which potatoes have been cooked is sometimes used for a part of the liquid in bread. Because of the development of rope in hot weather, it is often desirable in home-made bread to add the whey of sour milk during the summer. The best proportion of water varies with the hydration capacity of the gluten in the particular flour that is being used. The proportion as reported in the literature varies from about 51 to 67 per cent. Good bread flours usually require from 60 to 65 per cent of water. Soft-wheat flours, w^hich have weaker glutens, require a lower proportion of water. Effect of proportion of water used. The proportion of water used affects the tenacity and extensibility of the gluten and hence the resulting dough. PROPORTION OF INGREDIENTS USED IN BREAD 427 Bailey and Le Vesconte have found that the extensibility of the dough increased with increasing water content until an imbibition equivalent to 64 per cent of the weight of the flour was obtained. Further increase of water and increased hydration decreased the extensibility of the dough. The following table is from their results with the Chopin extensimeter.