Loss of Carbon in the Form of Alcohol

"During the fermentation process in bread making, the production of carbon dioxide is accompanied by the production of alcohol. Theoretically, for every part of carbon dioxide gas formed there is also produced 1.04 parts of alcohol. It is generally supposed that, during baking, the alcohol is entirely given off. The above theoretical experiments, when calculated on the basis of amounts of alcohol formed during bread making in the the carbon dioxide evolved, would be as follows, in the short-fermentation process: (1) 1.10 per cent, alcohol: (2) 1.13 per cent, alcohol; (3) 1.04 per cent, alcohol. Similar values for the long-fermentation process would be: (5) 0.83 per cent, alcohol.; (6) 0.94 per cent, alcohol; (7) 1 per cent, alcohol; (8) 1.07 per cent, alcohol; general average, 1.02.

"On an average there is about 1 per cent, by weight of alcohol produced when bread is made. It serves a useful purpose. In baking, the alcohol is volatilized and the vapor aids the carbon dioxide in expanding the dough, thus making the bread more porous.

"Samples of normal fresh bread were subjected to distillation and to other tests, but the distillate did not contain enough alcohol to give an appreciable reaction.

"In general it may be said that there is on an average about 1 per cent, of alcohol formed during bread making, and no appreciable amount of this alcohol is left in the bread. Production of Soluble Carbohydrates in Bread Making.

"In wheat flour, the carbohydrates are present mainly in the form of insoluble starch. There are, however, a number of other insoluble carbohydrates and small amounts of soluble carbohydrates, chiefly in the form of dextrin, with a small amount of sucrose.

"The soluble carbohydrates of wheat investigated by the Division of Chemistry were invert sugar, sucrose, and dextrin or galactin.

"In addition to the soluble carbohydrates mentioned above, small amounts of raffinose have been reported by several investigators in wheat germs. Wheat germ contains more sucrose than any other of the wheat products, and the amount of soluble carbohydrates in wheat flour depends largely upon the proportion of germ present.

"A sample of flour (No. 2) used in the experiments at the Minnesota Station to determine the extent to which starch is changed to soluble forms in bread making contained 1.62 per cent, of soluble carbohydrates, calculated as dextrin.

"In addition to the production of alcohol and carbon dioxide gas by fermentation, the action of the yeast and heat results in the production of soluble carbohydrates from insoluble forms. During the baking process, the heat changes some starch to dextrin. In the process of bread making, this results in both the consumption and production of soluble carbohydrates. The extent to which insoluble starch is changed to soluble forms in bread making is a subject which does not appear to have been extensively investigated. Koenig states that fine wheat bread contains 4.02 per cent, sugar and coarse bread 2.08 per cent. The term 'sugar,' however, is not defined.

"The extent to which soluble carbohydrates are either consumed or produced during bread making is an important matter, because flour contains on an average sixty-five per cent, or more of starch, and any change affecting the starch has a direct effect upon both the composition and value of the bread produced. In order to determine the extent to which soluble carbohy-drates are produced, six experiments were made. In three experiments the bread was made by the short-fermentation process, and in three other experiments by the long-fermentation process."

The following from the same bulletin shows that there is a loss of food value as well:

"Under the conditions of these experiments, there was an average loss of 1.58 per cent, of total dry matter, and 1.45 per cent, of the total nitrogen. The difference between the amount of nitrogen in the bread and that in the flour and yeast is so small that it might well be questioned whether this loss is not within the limits of error of ordinary chemical work."

While the amount of nitrogen lost when bread is properly made is small, the amount lost when bread is not properly made may materially exceed the figures given in the experiments to which reference has just been made.

Using a yeast of questionable quality, the bread maker has no assurance that she will have a perfect loaf, though the best of flour may be used, and the greatest attention given to all necessary conditions.

Any yeast which answers the required conditions will bring satisfactory results. We have no good means by which to know, on looking at a cake of dry yeast or a cup of liquid yeast, whether there is a sufficient number of germs in such a state of activity as to enable it to make the dough light in so short a time that the other ferments, which are always present in commercial yeast, will not be able to produce a deleterious effect upon the elements of the flour. Therefore it is wise to test the yeast with a small amount of sponge first.

Besides the yeast, one needs only a little salt, a known quantity of liquid, and sufficient flour to make a dough of the proper consistency, in order to be able to make bread of the best quality. The liquid may be water, or milk and water, or milk alone, but the milk must be always positively sweet, and it is safer in summer to scald and cool before using. Bread made with water is tougher than that made with milk. French bread is mixed with water alone, Vienna bread with milk and water, and there are several varieties in which milk is the only liquid used.

There is no good reason for putting butter or fat of any kind into bread, but there is an excellent reason for leaving it out, as it retards the action of the yeast. Sugar is not needed, since flour furnishes all that is necessary for the growth and multiplication of the yeast. The addition of any or all superfluous things will cause unnecessary labor, and be found worse than useless.

The amount of flour which it is necessary to mix with a certain amount of liquid to make dough of the proper consistency cannot be given by either weight or measure, without knowing the special brand of flour to be used, as the quantity varies according to the quality, because flours differ so greatly in their ability to absorb and retain liquids. There is, however, an unerring rule for determining the amount of liquid necessary in using any given flour. When a sufficient amount of flour has been added to the liquid measured out, the dough will be of such consistency that it can be handled without flour, and will not adhere to the hands or to the moulding board.

Of patent flour, one quart of liquid will require from three pounds and ten ounces to five pounds, or from three and one-half quarts to five quarts, of flour, and the amount of dough formed from these proportions of liquid and flour will make four medium-sized loaves, or about five pounds of good bread.

Stirred bread, or bread in which the manipulations are performed wholly with a spoon, stirring and cutting the ingredients together, and shaping the loaf with a knife, does not yield the best results. Nearly all the work may be done with utensils, using the hands in contact with the dough very little, and good bread produced. A loaf of bread, when properly baked, is cooked entirely through, and has a crust of a chestnut-brown color all over the top, bottom, sides, and ends. In order to accomplish this, the loaf must be small enough so that the center can be cooked without rendering the crust too thick or too brown.

The pan which will best serve this purpose measures four inches across the bottom, is three and one-half inches in height, and is as long as the oven will admit. Russia iron is the best material for pans. Sheet-iron will give equally good results in baking, but it, is difficult to keep in order, as it rusts easily. Tin does not give satisfactory results.

Bread which is not sufficiently baked deteriorates rapidly, and will, in a few days, become unpalatable, if not unfit for use; while bread which is perfectly baked will keep in a good condition a much longer time, simply becoming dry and hard, while that which is imperfectly baked becomes moldy, ropy, and may have a bad odor, because the spores of mold and the bacteria have not been killed.

The temperature of the oven at the time the bread is put into it should be about 375° F., with an increasing heat during the first few minutes. At this temperature, rolls will bake in twenty-five or thirty minutes. A loaf of the size and shape described above, in fifty to sixty minutes. A loaf of bread sufficiently baked will emit a hollow sound when tapped on the bottom. As soon as the loaf comes from the oven, it should be removed from the pan and brushed lightly all over with milk or fat, and placed uncovered in such a position as will expose most of the surface to the fresh air. It should not be allowed to come in contact with anything which may impart to it an unpleasant odor. When cold it should be placed in a tin box or similar receptacle, covered, and kept in a cool, dry place. It is not well to wrap bread in cloths, as it has better flavor when simply kept in a clean vessel.

The best utensils for bread making are an earthen bowl, a wooden spoon, and a medium-sized moulding board, with cleats to prevent moving on the table. A wooden spoon is more noiseless and more easily handled than one of metal. The earthen bowl is easily kept clean and in good condition. It is easy to keep the dough at an even temperature, while rising, in such a bowl.

Many people are seriously disturbed for hours by eating sour bread in which a long time between first setting the dough and baking has allowed acetic and other undesirable ferments to act in producing acids and other deleterious substances in the bread. Whole families are made dyspeptic by poor bread making. But the lack of good flavor, and the presence of acids which disturb digestion are far greater injuries than the mere loss of food nutrients.

Experiments have proven that yeast formed in contact with air having the maximum of free oxygen that it can assimilate is fresher and is possessed of greater vital activity than that which has been formed with an insufficiency of air. In manufactories of yeast, this fact is taken advantage of. The saccharine worts, after the addition of yeast, are left to themselves in shallow vats of large superficial area, that the air may act upon them. Under such conditions, the yeast develops and multiplies rapidly. The white froth which soon covers the surface of the fermenting liquid is skimmed off into vats of cold water, allowed to settle to the bottom, the water pumped off, the contents of the vat drained, and by a series of manipulations it is reduced to masses of the size and form known in the market as "compressed yeast." The yeast is in a state of vigorous growth acquired under the influence of free oxygen, since all the manipulations are made in contact with air, and the mass is impregnated more or less with oxygen. The yeast immediately seizes upon this gas, and acquires a state of freshness and activity which renders it valuable as a ferment.

The fact that compressed yeast is expensive and spoils readily is sometimes made an objection to its use. If kept where very cold, it will keep in good condition a week or more (if fresh when procured), and when properly manipulated it never fails to made good bread with a comparatively small amount of labor, with no worry, and no loss of material.

This yeast keeps better when removed from the tinfoil wrapper, put in a glass jar, and covered with cold water. The water should be poured off each day, and fresh water put on. Dry yeast cakes may be kept longer than compressed yeast, but in time they also lose their vitality.

Many people pay a high price for coarse flours, believing that they obtain more protein and mineral matter in these than in the finer flours. Late scientific investigations lead to the belief that not all so-called whole-wheat flour is genuine.

*"The bread made from the imitation whole-wheat flours contained less protein than bread made from the patent and bakers' grades of flour, while the bread made from true whole-wheat flours - that is, flours from which none of the germ or other parts of the wheat had been removed - contained about one per cent. more protein than bread made from ordinary flour. No conclusions, how*U. S. Dept. Agr., Office Exp. Stations, Bulletin No. 67.

NOTE - For further information on bread and bread making-see (1)U. S. Dept. Agr., Office Exp. Stations, Bulletin No. 67; (2) U. S. Dept. Agr., Farmers' Bulletin No. 112; (3) University of Minnesota, Agr. Exp. Station, Chemical Division, Bulletin No. 54; (4) The Science & Art of Bread Making - Jago; (5) U. S. Dept. Agr., Office Exp. Stations. Bulletin No. 34.

ever, as to the relative nutritive value of whole wheat and ordinary flours can be drawn from the figures given. The rye bread contained slightly less protein than ordinary wheat bread, while the corn bread contained less than the rye." Potato Yeast.

Take six large potatoes, pare, slice, and boil in one quart of water. Soak three dry yeast cakes in one cup of water. When the potatoes are done, mash through a colander, and then add the water (one quart), one and one-half tablespoonfuls of salt, and two and one-half ta-blespoonfuls of sugar. When cool, add the dissolved yeast cakes, set away in a temperature of about 75° F., and let stand twelve hours, when it is ready for use. The water used should be that in which the potatoes were cooked, with enough added to make a quart.