The Boston cooking-school cook book

If a crisp crust is desired, allow bread to cool without covering; if soft crust, cover with a towel during cooling. When cool, put in tin box or stone jar, and cover closely. Never keep bread wrapped in cloth, as the cloth will absorb moisture and transmit an unpleasant taste to bread. Bread tins or jars should be washed and scalded twice a week in winter, and every other day in summer; otherwise bread is apt to mould. As there are so many ways of using small and stale pieces of bread, care should be taken that none is wasted. =Unfermented bread= is raised without a ferment, the carbon dioxide being produced by the use of soda (alkaline salt) and an acid. Soda, employed in combination with cream of tartar, for raising mixtures, in proportion of one-third soda to two-thirds cream of tartar, was formerly used to a great extent, but has been generally superseded by baking powder. =Soda bicarbonate= (NaHCO_{3}) is manufactured from sodium chloride (NaCl), common salt or cryolite. =Baking powder= is composed of soda and cream of tartar in definite, correct proportions, mixed with small quantity of dry material (flour or corn-starch) to keep action from taking place. If found to contain alum or ammonia, it is impure. In using baking powder, allow two teaspoons baking powder to each cup of flour, when eggs are not used; to egg mixtures allow one and one-half teaspoons baking powder. When a recipe calls for soda and cream of tartar, in substituting baking powder use double amount of cream of tartar given. These rules apply to the various soda and cream of tartar baking powders on the market. Horsford’s Baking Powder, the only mineral one, requires one-third less than others. Soda and cream of tartar, or baking powder mixtures, are made light by liberation of gas in mixture; the gas in soda is set free by the acid in cream of tartar; in order to accomplish this, moisture and heat are both required. As soon as moisture is added to baking powder mixtures, the gas will begin to escape; hence