Yeast in bread.—Yeast is put into bread dough in order to produce carbon dioxide gas to lighten the whole mass. It is studied in the chapter on preservation of fruit, but in bread making we need to foster its growth instead of destroying it as, you will recall, we found necessary in preserving. You can easily reason out for yourself just how this should be done, especially after performing the experiments with yeast.
If yeast is in good condition, it has little effect on the flavor of bread, even if used in a rather large quantity to hasten the process.
The best forms of yeast now in use are the compressed and dried cakes, the former needing to be fresh, the latter
keeping the vitality of the yeast cells for a long time. Liquid yeast may be made at home, but it is somewhat uncertain unless made with great exactness, and less easy to manage on the whole than the other forms.
Proportions of the ingredients.—One part of water to three of flour, or one cup to three of flour for a loaf, is an average proportion. The practiced bread maker will vary this slightly to suit the variations in the flour from time to time, but it is a safe rule for the beginner to follow. Spring wheat flour requires somewhat more water than the winter wheat, or the blend of the two. Salt should be used sparingly, for although it improves the flavor of the loaf, salt is a preservative which retards or prevents the growth of lower organisms, and in the case of bread it acts therefore as a check to fermentation. One teaspoonful to a loaf is the largest amount that it is best to use.
The quantity of yeast depends upon several conditions. The larger the amount of yeast used, the shorter is the time of rising, and as many as two compressed yeast cakes may be used to one loaf if it is necessary to hasten the process, without any perceptible effect on the color, texture or flavor. If a very large amount of yeast is used, the bread is “crumbly,” and a difference in flavor will be noticed. A smaller amount may be used if time is allowed for the rising, even 1⁄8 cake of compressed yeast to a loaf, if the bread is to rise over night in warm weather. It must be remembered that, if the rising process is too prolonged, other organisms have a chance to work, and the bread may sour.
A small amount of sugar hastens fermentation, and from one to two teaspoonfuls to a loaf may be used. Many people prefer the flavor of bread with no sugar, however. Some bakers use malt extract both as a yeast food to hasten fermentation and for its effect upon the flavor.
Fat, or shortening, should be sparingly used, not more than one or two teaspoonfuls being allowed to a loaf. If you study a number of bread recipes, you will see that this ingredient varies more than the others. As a matter of fact, if the flour is of good quality and the bread well made, this ingredient is not necessary (in loaf bread at least), although it seems to improve the quality of biscuit and rolls.
Methods of mixing and the rising of bread.—Dissolve the yeast in a portion of the liquid, stir this mixture into the remaining liquid, add half the flour, and beat the mixture thoroughly at this stage. Add the sugar if any is to be used. When this soft mixture, called the “sponge,” becomes full of bubbles, add the salt, the shortening if used, and the remaining flour. Knead the dough by the hand, or by the machine, for about ten minutes, or until it is smooth and elastic. Put it into a greased bowl, cover the bowl, and allow the dough to remain until it doubles its bulk. Some bread makers knead in all the flour at the first, and obtain a good result. The first rising is more rapid, however, and experience seems to prove that the results are better on the whole with the sponge. Cut the dough down, knead again, using as little flour as possible. Shape into loaves, place the loaves in greased pans, cover, and leave again until the loaves double their bulk, when they are ready for baking. If left too long, the bubbles of gas become too large.