5. Estimate the weight in grams of each baking powder that would be required to raise one cup of flour. (It is supposed that 475 grams of carbon dioxide are needed to raise one pound of flour.) Compare the amount of bak- ing powder needed according to your estimate with that called for in your recipes. Account for the discrepancy, if there is one. In the commercial baking powders from 20-25 per cent of starch is used as a '^ filler " to pre- vent the ingredients from acting on one another. This should be allowed for in your estimate. Note on "The Effect of Combining Diiferent Leavens," etc. I (a). When baking soda alone is used as a leaven there ^^all be an evolution of carbon dioxide from its decomposition by heat. The volume of gas given off will be in proportion to the amount of soda used, and the mixture will rise "in proportion to the volume of gas. But the method prescribed in this step is meant to be a warning rather than an example, for the residue left after the decomposition of the 162 PRINCIPLES OF FOOD PREPARATION carbonate vnW discolor the flour mixture and impart an unpleasant taste and odor. It is hardly necessary to say that the product is unwhole- some, for the disagreeable effects will be a safeguard against its being eaten in such quantity as to do harm. I (6) . In the souring of milk only a very small amount of lactic acid is formed, from .4 per cent (when the milk will taste sour) to 1 per cent. It is true that other acids are usually present, but the total acidity in milk is seldom sufficient in amount to call for enough soda to give off enough carbon dioxide to raise the mixture. If the acid is present in too small amount to decompose the proportion of soda usually prescribed, that is, one teaspoonful to a pint of milk, the excess of the soda will be de- composed under the influence of heat, thus liberating the gas, but dis- coloring the mixture in the same way, though not to the same extent, as when soda alone is used as a leaven. (See I, (a).) The correct amount of soda to use with sour milk can be deter- mined scientifically by experimenting with a small quantity of the milk, adding soda to it in definite small amounts, testing with litmus after each addition, and when the neutral point is reached calculating the amount needed for the volume of milk to be used for the particular mixture in hand. The long patience necessary for such a process will dissuade most of us from attempting it, as will the knowledge that such painstaking would be scorned by our grandmothers, who added their saleratus to the milk "according to their judgment," and could unerringly tell by tasting the mixture whether or not they had added enough. I (c). Recalling what has been stated under I (h), it may be in- ferred that soda alone, measure ye never so wisely, will not find enough acid in sour milk to act upon with the result of liberating enough gas to raise the mixture. Therefore, in practice it is found that baking powder, if added in equal amount with the soda, will give the desired lightness, while the better flavor of the sour milk cakes will be present. I (d). The muffin made by this process is meant to be the standard, as regards the degree to which it has risen. If muffin (c) is higher this signifies that so much baking powder need not have been used as an aid to the soda and acid.

AI-modernized reading of the original text

5. Estimate the weight in grams of each baking powder that would be required to raise one cup of flour. (It is supposed that 475 grams of carbon dioxide are needed to raise one pound of flour.) Compare the amount of baking powder needed according to your estimate with that called for in your recipes. Account for the discrepancy, if there is one. In the commercial baking powders from 20-25 per cent of starch is used as a '^ filler " to prevent the ingredients from acting on one another. This should be allowed for in your estimate. Note on "The Effect of Combining Diiferent Leavens," etc. I (a). When baking soda alone is used as a leaven there will be an evolution of carbon dioxide from its decomposition by heat. The volume of gas given off will be in proportion to the amount of soda used, and the mixture will rise "in proportion to the volume of gas. But the method prescribed in this step is meant to be a warning rather than an example, for the residue left after the decomposition of the carbonate will discolor the flour mixture and impart an unpleasant taste and odor. It is hardly necessary to say that the product is unwholesome, for the disagreeable effects will be a safeguard against its being eaten in such quantity as to do harm. I (6) . In the souring of milk only a very small amount of lactic acid is formed, from .4 per cent (when the milk will taste sour) to 1 per cent. It is true that other acids are usually present, but the total acidity in milk is seldom sufficient in amount to call for enough soda to give off enough carbon dioxide to raise the mixture. If the acid is present in too small amount to decompose the proportion of soda usually prescribed, that is, one teaspoonful to a pint of milk, the excess of the soda will be decomposed under the influence of heat, thus liberating the gas, but discoloring the mixture in the same way, though not to the same extent, as when soda alone is used as a leaven. (See I, (a).) The correct amount of soda to use with sour milk can be determined scientifically by experimenting with a small quantity of the milk, adding soda to it in definite small amounts, testing with litmus after each addition, and when the neutral point is reached calculating the amount needed for the volume of milk to be used for the particular mixture in hand. The long patience necessary for such a process will dissuade most of us from attempting it, as will the knowledge that such painstaking would be scorned by our grandmothers, who added their saleratus to the milk "according to their judgment," and could unerringly tell by tasting the mixture whether or not they had added enough. I (c). Recalling what has been stated under I (h), it may be inferred that soda alone, measure we never so wisely, will not find enough acid in sour milk to act upon with the result of liberating enough gas to raise the mixture. Therefore, in practice it is found that baking powder, if added in equal amount with the soda, will give the desired lightness, while the better flavor of the sour milk cakes will be present. I (d). The muffin made by this process is meant to be the standard, as regards the degree to which it has risen. If muffin (c) is higher this signifies that so much baking powder need not have been used as an aid to the soda and acid.

Principles of food preparation