Flour contains diastase, an enzyme not unlike the ptyalin found in saliva, which is capable of changing the starch into sugar. As soon as sugar is produced, the yeast begins to act upon it by means of the ferments which it contains. These break up the sugar present into carbon dioxide and alcohol. The carbon dioxide is a gas which cannot escape easily through the dough, since the gluten present holds it, much as the soap in soapsuds holds air when one blows into it. Gluten in flour is developed by kneading, since this mixes water with the glutenin and gliadin, two proteins found in flour. Many people have an idea that bread must be kneaded with great force, but this is a mistake. The more lightly the dough is handled, the better the tex- ture of the bread. As little flour as possible should be used, but, of course, enough must be added to enable the BREAD-MAKING 247 dough to be handled without sticking to the board or the fingers. Experience makes it possible to handle a very soft dough, and this is probably one of the ways in which skill counts in bread-making. As the yeast grows and produces carbon dioxide, the dough is stretched by the gas until it is full of bubbles, and "rises." The action is allowed to go on, until the dough has doubled in bulk. At this stage, it could be baked, but it would give a bread of very uneven texture, for, with all the care in mixing, the bubbles of gas are unevenly distributed and some are very large. So, instead of being baked, the dough is kneaded again, this time to break up the larger bubbles and to distribute the gas as evenly as possible. Then the dough is shaped into loaves. It is again set in a warm place for the yeast to produce more gas, since some was lost in the kneading process. When the dough has doubled in bulk, it is ready for baking. Fat is commonly added because the bread is " shorter", as it is called, that is, less tough . Sugar is sometimes added to hasten the starting of the yeast, as well as to make the bread more tender. Potatoes and potato water also seem to stimulate the yeast to quicker action, and to make the bread less dry after it is baked. Milk may be used as the liquid in place of part or of all of the water. It adds some fat as well as a little more food value to the bread and changes its flavor somewhat. If milk be used, it is first scalded to kill some of the bacteria present. There is always danger of the dough souring, because the yeast itself is not free from bacteria, and some kinds of bacteria act on the alcohol and produce acids which make the bread sour. In a short-process bread, there is less danger of sour dough, because the yeast usually acts too quickly to give the bacteria time to multiply sufficiently to produce enough acid to sour the dough. 248 FOOD STUDY The liquid must not be mixed with the yeast while it is too hot, or the yeast will be killed. Yeast plants cannot stand a temperature of 130° F.

AI-modernized reading of the original text

Flour contains diastase, an enzyme not unlike the ptyalin found in saliva, which is capable of changing the starch into sugar. As soon as sugar is produced, the yeast begins to act upon it by means of the ferments which it contains. These break up the sugar present into carbon dioxide and alcohol. The carbon dioxide is a gas which cannot escape easily through the dough, since the gluten present holds it, much as the soap in soapsuds holds air when one blows into it. Gluten in flour is developed by kneading, since this mixes water with the glutenin and gliadin, two proteins found in flour. Many people have an idea that bread must be kneaded with great force, but this is a mistake. The more lightly the dough is handled, the better the texture of the bread. As little flour as possible should be used, but, of course, enough must be added to enable the dough to be handled without sticking to the board or the fingers. Experience makes it possible to handle a very soft dough, and this is probably one of the ways in which skill counts in bread-making. As the yeast grows and produces carbon dioxide, the dough is stretched by the gas until it is full of bubbles, and "rises." The action is allowed to go on, until the dough has doubled in bulk. At this stage, it could be baked, but it would give a bread of very uneven texture, for, with all the care in mixing, the bubbles of gas are unevenly distributed and some are very large. So, instead of being baked, the dough is kneaded again, this time to break up the larger bubbles and to distribute the gas as evenly as possible. Then the dough is shaped into loaves. It is again set in a warm place for the yeast to produce more gas, since some was lost in the kneading process. When the dough has doubled in bulk, it is ready for baking. Fat is commonly added because the bread is " shorter", as it is called, that is, less tough . Sugar is sometimes added to hasten the starting of the yeast, as well as to make the bread more tender. Potatoes and potato water also seem to stimulate the yeast to quicker action, and to make the bread less dry after it is baked. Milk may be used as the liquid in place of part or of all of the water. It adds some fat as well as a little more food value to the bread and changes its flavor somewhat. If milk be used, it is first scalded to kill some of the bacteria present. There is always danger of the dough souring, because the yeast itself is not free from bacteria, and some kinds of bacteria act on the alcohol and produce acids which make the bread sour. In a short-process bread, there is less danger of sour dough, because the yeast usually acts too quickly to give the bacteria time to multiply sufficiently to produce enough acid to sour the dough. The liquid must not be mixed with the yeast while it is too hot, or the yeast will be killed. Yeast plants cannot stand a temperature of 130° F.

Food study