Gluten, the proteid of wheat, is a gray, tough, elastic substance, insoluble in water. On account of its great power of expansion, it holds the gas developed in bread dough by fermentation, which otherwise would escape.
Yeast
Yeast is a microscopic plant of fungous growth, and is the lowest form of vegetable life. It consists of spores, or germs, found floating in air, and belongs to a family of which there are many species. These spores grow by budding and division, and multiply very rapidly under favorable conditions, and produce fermentation.
Fermentation is the process by which, under influence of air, warmth, moisture, and some ferment, sugar (or dextrose, starch converted into sugar) is changed into alcohol (C2H5HO) and carbon dioxide (CO2). The product of all fermentation is the same. Three kinds are considered,—alcoholic, acetic, and lactic. Where bread dough is allowed to ferment by addition of yeast, the fermentation is alcoholic; where alcoholic fermentation continues too long, acetic fermentation sets in, which is a continuation of alcoholic. Lactic fermentation is fermentation which takes place when milk sours.
Liquid, dry, or compressed yeast may be used for raising bread. The compressed yeast cakes done up in tinfoil have long proved satisfactory, and are now almost universally used, having replaced the home-made liquid yeast. Never use a yeast cake unless perfectly fresh, which may be determined by its light color and absence of dark streaks.
The yeast plant is killed at 212° F.; life is suspended, but not entirely destroyed, 32° F. The temperature best suited for its growth is from 65° to 68° F. The most favorable conditions for the growth of yeast are a warm, moist, sweet, nitrogenous soil. These must be especially considered in bread making.
Bread Making
Fermented bread is made by mixing to a dough, flour, with a definite quantity of water, milk, or water and milk, salt, and a ferment. Sugar is usually added to hasten fermentation. Dough is then kneaded that the ingredients may be thoroughly incorporated, covered, and allowed to rise in a temperature of 68° F., until dough has doubled its bulk. This change has been caused by action of the ferment, which attacks some of the starch in flour, and changes it to sugar, and sugar in turn to alcohol and carbon dioxide, thus lightening the whole mass. Dough is then kneaded a second time to break bubbles and distribute evenly the carbon dioxide. It is shaped in loaves, put in greased bread pans (they being half filled), covered, allowed to rise in temperature same as for first rising, to double its bulk. If risen too long, it will be full of large holes; if not risen long enough, it will be heavy and soggy. If pans containing loaves are put in too hot a place while rising, a heavy streak will be found near bottom of loaf.
How to Shape Loaves and Biscuits. To shape bread dough in loaves, divide dough in parts, each part large enough for a loaf, knead until smooth, and if possible avoid seams in under part of loaf. If baked in brick pan, place two loaves in one pan, brushed between with a little melted butter. If baked in long shallow pan, when well kneaded, roll with both hands to lengthen, care being taken that it is smooth and of uniform thickness. Where long loaves are baked on sheets, shape and roll loosely in a towel sprinkled with corn meal for last rising.
To shape bread dough in biscuits, pull or cut off as many small pieces (having them of uniform size) as there are to be biscuits. Flour palms of hands slightly; take up each piece and shape separately, lifting, with thumb and first two fingers of right hand, and placing in palm of left hand, constantly moving dough round and round, while folding towards the centre; when smooth, turn it over and roll between palms of hands. Place in greased pans near together, brushed between with a little melted butter, which will cause biscuits to separate easily after baking. For finger rolls, shape biscuits and roll with one hand on part of board where there is no flour, until of desired length, care being taken to make smooth, of uniform size, and round at ends.