Unleavened bread is particularly advisable for use in emergency rations for marching soldiers, in logging camps, etc. This bread is compact, comparatively free of moisture and has a high nutritive value. The leavened bread may be divided into distinct classes in respect of the leavening agent employed.
Class 1 is bread in which the leavening agent is yeast. Class 2 is bread in which the natural ferments residing in the flour or wheat are utilized for the leavening agent as in the making of that variety known as salt rising bread. Class 3 includes that form of bread in which the leavening is secured by chemical reagents mixed with the dough. Class 4 includes that variety in which a leavening reagent such as carbon dioxid or air is mechanically incorporated with the dough during the kneading process.
Unleavened bread is also divided into several technical forms. The first class includes the biscuit of commerce, sometimes incorrectly called crackers, and intended to be used soon after preparation. The second class includes biscuits which are intended for long storage and transportation. The third class includes wafers and other delicate forms of unleavened bread for special use. Class 4 is the unleavened loaves which are made most frequently from Indian corn meal and intended to be eaten while still hot. Class 5 includes any miscellaneous unleavened loaves or cakes made in various ways and for different purposes.
In nearly all forms of unleavened bread made from wheat flour the dough is thoroughly beaten, and mechanically mixed or kneaded, in order to make it lighter in color and more crisp and hard after baking.
Yeast.
—Bakers’ yeast is one form of the ordinary yeast ferments or a mixture thereof producing alcoholic fermentation under proper conditions. All flour contains a certain quantity of sugar which is easily fermented. By the action of the yeast upon this sugar carbon dioxid and alcohol are formed. The particles of carbon dioxid become entangled in the gluten of the wheat flour when it is mixed into a dough and thus make the mass spongy and light. When placed in the oven to be baked these minute particles of carbon dioxid expand still more and produce additional lightness and sponginess of the loaf. The yeast may be propagated from one mass of dough to another, may be used in a moist state or, as is very commonly the case, manufactured in large quantities, and sold either moist or more commonly in a partially dried and pressed cake.
Spontaneous Ferments.
—All cereals contain ferments of a character to produce alcoholic fermentation spontaneously under proper conditions. It is possible even to ferment dough by seed from one loaf to another or by developing a spontaneous fermentation. This method is quite a common one in the rural districts, and all bread made in this way is known as salt rising bread. It may be made according to the following receipt:
A quarter of a pint of fresh whole milk is slowly heated to near the boiling point, but not allowed to boil. This process will sterilize the milk and prevent the development of a too rapid lactic fermentation in the subsequent processes. The heated milk is added to a quantity of maize meal sufficient to make with the milk a stiff batter, and the whole is thoroughly mixed. The vessel containing the batter is wrapped with paper and then with a heavy flannel cloth, and kept in a warm place at a uniform temperature of about blood heat for several hours, until fermentation is fully established and the batter assumes a definite sour odor. At this point a teaspoonful of salt is stirred into a pint of blood-warm water and into this a sufficient quantity of high-grade wheat flour is stirred to make a moderately stiff batter. This is thoroughly mixed with the sour mass obtained by the previous fermentation and the mixture exposed for from three-fourths to one hour to a blood heat as before. If the fermentation has been well conducted the mass will now be in a sufficiently active state to secure a proper porosity of the loaf. The salt rising thus prepared is mixed with a wheat flour dough made with warm water in sufficient quantities to make from four to six loaves, the whole mass well kneaded, molded into loaves and put aside at a temperature of blood heat until the fermentation has proceeded far enough to make the loaf light and spongy. The loaf is then baked in the ordinary way.