The two most practicable methods of making bread are with yeast, and with cream of tartar and bicarbonate of soda.
Yeast is a micro-organism - an exceedingly minute form of plant life - which by its growth produces carbonic acid and alcohol. When this growth takes place in a mass of flour dough, the carbonic acid generated, in its effort to escape, puffs it up, but, owing to the viscous nature of the gluten, it is entangled and held within. Each little bubble of gas occupies a certain space. When the bread is baked, the walls around these spaces harden in the heat, and thus we get the porous loaf.
Barley, rye, and some other grains would be very useful for bread if it were not that they lack sufficient gluten to entangle enough carbonic acid to render bread made from them light.
Good bread cannot be made without good flour. There are two kinds usually to be found in market, namely bread flour, and pastry flour. The former is prepared in such a way that it contains more gluten than the latter. In making Pastry, or St. Louis flour, as it is sometimes called, the grain is crushed in such a manner that the starch, being most easily broken, becomes finer than the gluten, and in the process of bolting some of the latter is lost. For pastry and cake this kind is best. Lacking gluten, bread made from it is more tender, whiter, but less nutritious than that made from so-called bread flour.
New Process, or bread flour may be distinguished by the " feel," which is slightly granular rather than powdery, by its yellow color, and by the fact that it does not " cake " when squeezed in the hand; while St. Louis is white, powdery, and will "cake."
The best method to pursue in buying flour is, first, to find a good dealer, upon whose advice you may rely. Next, take a sample of the flour recommended and, with a recipe which you have proved to be correct, try some; if the first loaf of bread is not satisfactory, try another, and then another, until you are confident that the fault lies in the flour, and not in the method of making. Finally, having found a brand of flour from which you can make yellow-white instead of snow-white bread, which has a nutty, sweet flavor, which in mixing absorbs much liquid, and - does not "run" after you think you have got it stiff enough, and which feels puffy and elastic to the hand after molding, keep it ; it is probably good.
Often the same flour is sold in different sections of the country under different names, so that it is impossible to recommend any special brand. Each buyer must ascertain for herself which brands in her locality are best. It is just as easy to have good bread as poor. It only requires a little care and a little intelligence on the part of the housekeeper.
Having found a brand of good flour, next give your attention to yeast. In these days, when excellent compressed yeasts may be found in all markets, it is well to use them, bearing in mind that they are compressed, and that a very small quantity contains a great many yeast cells, and will raise bread as well, if not better, than a large amount.
Home-made liquid yeast is exceedingly easy to prepare. It simply requires a mixture of water and some material in which the plant cells will rapidly grow. Grated raw potato, cooked by pouring on boiling water, flour, and sugar form an excellent food for their propagation. A recipe for yeast will be given later.
Now we have come to the consideration of what will take place when the two, flour and yeast, are made into dough. According to some accounts of the subject, the yeast begins to act first upon the starch, converting it into sugar (glucose CaH1206). While this is taking place there is no apparent change, for nothing else is formed except the glucose, or sugar. Then this sugar is changed into alcohol and carbonic acid; the latter, owing to its diffusive nature, endeavors to escape, but becomes entangled in the viscous mass and swells it to several times its original bulk.
This has been the accepted explanation; it is now, however, believed not to be correct. It is thought, and I believe demonstrated, that the yeast plant lives upon sugar; that it has not the power to act directly upon starch, but that it is capable of producing a substance which acts upon starch to convert it into sugar.
The production of the carbonic acid is the end of desirable chemical change, and when it has been carried to a sufficient degree to fill the dough with bubbles, it should be stopped.
Kneading bread is for the purpose of distributing the gas and breaking up the large bubbles into small ones, to give the loaf a fine grain. One will immediately see that kneading before the bread is raised is a more or less useless task. Kneading is a process which should be done gently, by handling the dough with great tenderness; for if it is pressed hard against the molding-board, the bubbles will be worked out through the surface, and the loaf consequently less porous than if all the gas is kept in it.
The best temperature for the raising of bread (in other words, for the growing of yeast) during the first part of the process is from 70° to 75° Fahr. It may touch 80° without harm, but 90° is the limit. Above that acetic fermentation is liable to occur, and the bread becomes sour. When the bread is made into loaves, it may be placed in a very warm temperature, to rise quickly if it is intended for immediate baking. Besides killing the yeast, the object sought in baking is to form a sheath of cooked dough all over the outside, for a skeleton or support for the inside mass while it is cooking. Baking also expands the carbonic acid, and volatilizes the alcohol. The latter is lost.
A good temperature in which to begin the baking of bread is 400° Fahr. This may gradually decrease to not lower than 250°, and the time, for a good-sized brick loaf, is one hour. If it is a large loaf, increase the time by a quarter or a half hour.
" The expansion of water or ice into 1700 times its volume of steam, is sometimes taken advantage of in making snow bread, water gems, etc. It plays a part in the lightening of pastry and crackers. Air at 70° Fahr. expands to about twice its volume at the temperature of a hot oven, so that if air is entangled in a mass of dough it gives a certain lightness when the whole is baked. This is the cause of the sponginess of cakes made with eggs. The viscous albumen catches the air and holds it."
There are other means of obtaining carbonic acid to lighten bread, besides by the growing of yeast. The most convenient, perhaps the most valuable, method is by causing cream of tartar and bicarbonl Mrs. Richards.
ate of soda to unite chemically. (The products of the union are carbonic acid and Rochelle salts.) The advantage of using these over everything else yet tried is, that they do not unite when brought in contact except in the presence of water and a certain degree of heat. Rochelle salts, taken in such minute quantities as it occurs in bread made in this way, is not harmful.
Cream of tartar bread, if perfectly made, is more nutritious than fermented bread, for none of the constituents of the flour are lost, as when yeast is used.1
The difficulty of obtaining good cream of tartar is very great. It is said to be more extensively adulterated than any other substance used for food. Moreover, in the practice of bread-making the cream of tartar and soda are generally mixed in the proportion of two to one - that is, two teaspoons of cream of tartar to every teaspoon of soda; but this is not the exact proportion in which they neutralize each other, so that under ordinary circumstances there is an excess of soda in the bread.
To be exact they should always be combined by weight, as is done in making baking-powders, the proportion being 84 parts of soda to 188 of cream of tartar, or, reducing to lower terms, as 21 to 47 - a little less than half as much soda as cream of tartar. For practical use in cooking there are no scales known to the author for the purpose of weighing these materials, so the proportion will have to be approximated with teaspoons, and a fairly accurate result for bread-making may be obtained most easily by measuring a teaspoon of each in exactly the same manner, and then taking off a little from the soda.
1 A portion of the starch and sugar is consumed to feed the growing yeast. It has been estimated that about 1/7 of a barrel of flour is lost in raising bread - that is, that amount is consumed by the yeast used.
With good materials, care in measuring them, and a hot oven to set the bread before the gas escapes, cream of tartar biscuits are both wholesome and palatable.