In order that the same grade of flour may have always, as nearly as possible, the same strength and quality, some mills employ a person who makes into bread a certain weighed quantity of flour as often as is necessary to know the strength of the flour milled, and the proportions of glutenous and starchy wheats are varied as determined by the results.
Flours made from different kinds of wheat vary greatly in strength. Strong flour will rise high in loaf, and will absorb a large amount of water. The baker will pay more for strong flour, because from a hundred pounds of strong flour he can make a larger number of loaves than from weak flour. With flour of medium strength, the housewife can make loaves with beautiful crust, crumb fine, soft, and not quickly dried out, aromatic, and of nutty flavor,- such bread as will take the place of cakes and pies. Uniformity in strength is very much desired, so that the baker, having learned to make good loaves from a given sample of flour, can, with uniform treatment, always supply the family with choice loaves.
Strength is given a flour by the gluten, which forms about one-seventh of the weight of the flour. Gluten is made up of several nitrogenous compounds, mainly glia-din and glutenin. The proportion of these two sub-stances determines the strength of the gluten. Much gliadin and little glutenin makes a soft, sticky dough; an excess of glutenin and a small amount of gliadin makes weak dough; while wheat which has six parts gliadin to four parts glutenin makes a strong flour, which will rise high, and will retain its ability to rise till worked down two or more times. In bread making, dough should rise only once before moulding into loaves. (See Minnesota Bulletin No. 54.)
The food value of flour does not always correspond to its strength. The percentage of gluten has very much to do with its food value, since the flesh-forming gluten has more value per pound than the heat-forming starch, sugar, and cellulose. Flours vary from seven to eighteen per cent, of gluten. The standard flours from the northern mills have from twelve to fifteen per cent, of gluten.
The price of the best flour is often twice that of the lowest grades, because it is easier manipulated, makes a whiter loaf, with softer crumb, and a more palatable and more healthful bread. Such flours do not always contain food substances of greater value. In fact, the stockman might properly choose some of the low-grade flours for his animals, in preference to the best patent. The modern roller mills make several different grades of flours, as patent, bakers', and low-grade flour. The prices at wholesale are relatively as follows: Best Patent, $3.70 per bbl.; Straight, $3.50 per bbl.; First Bakers' Patent, $3.45 per bbl.; Second Bakers' Patent, $3.30 per bbl.; Low Grade (Red Dog) $17.00 per ton.
The chemical composition of these flours is shown in the following tables :
Dry Matter per cent
Ash per cent
Protein per cent
Carbohydrates per cent
See Jordan and Hall's Bulletin on Digestibility of Food Stuffs.
Red dog flour, on account of the poor quality of bread which it produces, is used mostly for stock feeding. The following is its composition, as given by Henry, in "Feeds and Feeding:"
Digestible Nutrients in 100 pounds.
Fertilizing Constituents in 1000 pounds.
in 100 pounds
Red Dog Flour......
| 90.3 |
In red dog flour are portions of the germ of the wheat, which, though made up of rich muscle-forming foods and of oils, are of such a mechanical nature as not to aid in making the loaf light.
The action of yeast in the dough is to produce gas by breaking up the starch and other compounds of the flour. This gas tries to escape by expanding, and in doing so enlarges within the minute interstices of the dough. As the gas accumulates, these interstices become larger, and the walls of gluten with entangled particles of starch are stretched out into thin plates. If the glutenous membrane is made up of the right proportions of glutenin and gliadin, without too much other proteids, it is tough, and may be stretched to a large size in thin sheets, just as a child at play may make very large bubbles if his mixture of soap and water is pure and properly combined.
When heat is applied in baking bread, the gluten is coagulated or hardened, just as an egg is hardened by heating, so that the thin plates separating the interstices lose their power of contracting, or of being further stretched. The desire is to have the bread light, yet with comparatively small interstices or pores in the crumb, preferably none larger than a kernel of wheat. To secure a fine crumb, the reworking of the dough, the time to place the loaf in the oven, and the heat of the oven must be so managed as to have the gluten hardened when the loaf is properly raised. Experience with a given brand of flour will enable the baker to determine the number of times to work the dough down, and the amount of kneading to give it; also the size to allow the loaves to rise the last time, so as to give the desired texture of crumb. If the oven is quite hot when the loaves are put in, a crust of coagulated gluten is soon formed, which will hold up the interior of the loaf, preventing the crumb from contracting into a sodden mass, as sometimes occurs when the oven is not hot, and the loaf is heated up too slowly.
Patent and other superior kinds of flour sell higher than the poorer grades, because their gluten, even though it be less in quantity, will stand up till baked into beautiful palatable loaves, and the crumb may be eaten without doughing up in the mouth. Fine white bread is at once cake and the staff of life. No other cake compares with it as a source of every-day enjoyment, and no other bread will take its place where civilization has introduced it. White bread is the most important dish of civilization. The woman who presents her family with perfect bread at every meal, and, with it, good butter and cold water or milk, has a basis upon which to feed any member of her family and every guest, whether well, sick, or notional. Good white bread and water are the two universal foods; no one tires of them.
A pound loaf of bread can be made from about three-quarters of a pound of flour, about twenty-five per cent, of water being added to the flour during the process of bread making. With some flours, five to ten per cent, more water can be absorbed, making a greater weight of bread product from a given weight of flour. This additional weight is water, and not nutrients. At two cents per pound for flour, it is estimated that a pound loaf of bread can be made, not counting fuel and labor, for about two cents; half a cent being allowed for shortening and yeast.
Next to the quality of the flour, the things which are of paramount importance in bread making are the quantity and quality of the yeast, the temperature at which the dough is kept while rising, and the length of time which is allowed to elapse between the time of adding the yeast to the mixture and the baking of the bread.
The discoveries in the new world - he world of little things - by Pasteur and others, have led to the preparation of yeast of superior quality.
"About the year 1875, some practical experiments were made in connection with the new process of brewing, and a yeast of irreproachable purity was cultivated and used. This yeast, which was repeatedly used during the summer of that year, always produced a beer of remarkable keeping properties, while beer made at the same brewing from the same wort by the ordinary process did not remain sound three weeks, though kept in the same cellar as the other."
It is not possible for us to have strictly pure yeast for use in bread making, and it might not be best for this purpose if we had it, but we can have yeast sufficiently pure to produce a quality of bread which is in every sense wholesome, palatable, and possessed of good keeping qualities. When compressed yeast cannot be obtained fresh, it is better to use home-made yeast, which can always be had fresh and vigorous.
In order to insure good results in bread making, no longer time than five hours should be allowed to elapse between the time that the ferment is set, and that at which the bread is taken from the oven. The temperature should range from 75 degrees to 80 degrees F., as this degreee of heat is favorable to the action of the yeast, but less favorable to the development and multiplication of the ferments present, which in their action produce deleterious effects. These, left a longer time than four hours, will accomplish some of their destructive work. A good example of the evil effects produced by giving too much time to fermentation can be frequently seen on some tables. Take a roll or biscuit, and you find it a sample of fermented bread of very good quality, but choose a slice of a loaf made the same day, and it is inferior in appearance, taste, and nutritive qualities. Investigation will usually prove that the ferment for loaf and rolls was set at the same time, and the rolls were baked for tea, while the loaves set an hour longer before going into the oven. A single simple experiment is suffix 4 cient to prove that the temperature at which the dough is kept while rising has a great influence on the quality of the bread produced. Mix at as nearly the same time as possible three portions of dough, using plenty of good yeast, and having all conditions except temperature the same in the three cases. Let one portion be mixed with a warm liquid, and set in a warm place to rise, at 90 degrees F., another mixed with a liquid at 65 degrees F., and a third at 75 degrees F., and allow to continue at those temperatures while rising, and, when baked, compare the loaves as to color, taste, and odor, and those who believe that much yeast yields the unpalatable product known as "yeasty bread" will notice that the loaf in which right conditions were followed gives off a pleasant odor, and has a fine flavor, though the same quantity of yeast was used as in the loaf which presents the unsightly appearance, and has the disagreeable taste and smell produced by too high or too low a temperature.
Loss of Dry Matter in Bread Making. *"In bread making, the action of the yeast and heat results in (1) the fermentation of the carbohydrates, and the production of carbon dioxide and alcohol; (2) the production of soluble carbohydrates, as dextrin, from insoluble forms, as starch; (3) the production of lactic and other acids; (4) the formation of other volatile carbon compounds; (5) a change in the solubility of the proteid compounds; (6) the formation of amid and ammonium compounds from soluble proteids; and (7) the partial oxidation of the fat. In addition to these changes there are undoubtedly many others which take place. Inasmuch as many of the compounds formed during the fermentation process are either gases or are volatile at the temperature of baking, appreciable losses of dry matter must necessarily take place in bread making. These losses are usually considered as amounting to about two per cent, of the flour used. In exceptional cases, as in prolonged fermentation, under favorable conditions the losses may amount to eight per cent, or more.
* Minnesota Bulletin No. 67.