( Originally Published Early 1900's )
Wheat is the most important of our bread stuffs. See geography for location of wheat fields and milling centers. Bring specimens of wheat, flour, bran, and rye flour.
Structure. The wheat grain is a small oval seed of a brownish yellow color. It has a hard outer covering, known as the husk, which is removed when the grain is threshed. Underneath this are fine layers of bran to which some starch and gluten adhere. Underneath these lie the gluten or protein mat-ter. Next to this, but closely connected with it, are the starch cells. The germ, which is rich in oil, lies at one end.
Composition. (See table, page 116, for per cent composition.) Wheat is particularly valuable in the making of yeast bread because of its gluten content, which permits the dough to stretch and retain the gas.
Graham Flour. In the making of Graham flour the whole grain is ground and the bran retained. Some poor grades of Graham flour are made of low grade white flour with a little bran added. Graham flour is valuable for those with a tendency to constipation, as it stimulates peristalsis.
Whole Wheat Flour. This is made from wheat from which ! two coverings of bran have been removed; it is darker than ordinary white flour. It, too, is stimulating. to peristalsis, owing to its oil and bran. As it has a high mineral content, bread made of whole wheat flour should be used if the diet is lacking in milk, fruit, and vegetables.
White Flour. In making white flour all the bran and the germ have been removed.
Pastry Flour. A high grade of white flour made from winter or soft wheat is known as pastry flour.
Rye Flour. Rye, like wheat, is used for flour. It is darker in color than wheat flour. Owing to the difference in the quality of its gluten it does not yield a loaf of the same lightness as does the wheat flour.
EXPERIMENT I. Examine and compare samples of all these flours. Sift and note the amount of waste material in each. What proportion of each passed through the sieve? How does the proportion differ?
Bleached Flour. Flour is bleached so that inferior grades may have the appearance of the best quality. In the bleaching process a chemical (nitrogen peroxide gas) is used, which leaves a trace in the flour. In buying flour see that the label states that it is unbleached. A dead whiteness may be due to bleaching, while a dark colored, slaty, or gray flour is poor. What does your pure food law say about bleached flour?
Selection of Flour. Wheat is classified as spring or hard wheat, and winter or soft wheat. Certain varieties of winter wheat, however, such as the Turkey Red wheat of Kansas, are known as hard wheats. Hard wheats yield a creamy, granular flour, rich in gluten, while soft wheats yield a white, smooth, starchy flour. The average flour is a blend of hard and soft wheat.
EXPERIMENT II. Granulation and Color of Flour.—Lay samples of different flour on a sheet of glass, arranging them in order of color. Compare these colors. How do the differences correspond with. the quality of the flour? Examine the flour with a microscope, noting any coarse or dark-colored particles of bran or dust. Rub some of the flour between the thumb and forefinger. Note if any granular particles can be detected. Can the texture be determined by the appearance?
The odor is a most important point in selecting flour. If it is at all sour the flour is spoiled ; if musty or rancid do not use it, as the mustiness is more apparent after the flour is made into bread.
Qualities of Good Bread Flour. Good bread flour is of a creamy white, is quite granular or grainy, and does not hold its shape when the hand is opened after the flour has been pressed together. It should feel dry rather than moist. The quantity of water taken up by the flour is an important point —from sixty to sixty-five per cent of its weight of water should be absorbed.
Pastry Flour. Good pastry flour is smooth and white and holds its shape when pressed in the hand.
Keeping Flour. Good white flour made from first class wheat improves with age if kept for a few months in a cool, well ventilated place. Flour made of poor material cannot be kept. If good flour can be procured buy it in quantity in the autumn. Graham or whole wheat flours do not keep well on account of the oil. Keep flour in a cool, dry place.
Composition of Flour. What food elements are found in flour? (See Table, page 116.) Wheat contains a sticky protein known as gluten. This varies from a high per cent in fine hard wheat to a small per cent in soft wheat.
EXPERIMENT III. Review Experiment VIII, page 45. If the gluten is dark and stringy the flour will not make good bread. What particular quality does such flour possess? Good flour should have at least thirty per cent of moist gluten. Bake a part of the washed dough and note appearance. What are the properties of gluten? Test Graham and whole wheat flour in the same way.
EXPERIMENT IV. Review Experiment III. Wash dough in 1/2 c. water, boil water, and test for starch.
Cornmeal is an important breadstuff in this country. It does not contain gluten and cannot be used for yeast bread. Only clean corn free from smut or weevils should be used for making meal. It is made by two processes known as the new and the old. In the new process a part of the germ is removed, and this gives meal of a peculiar flavor, which is poor in oil and takes up much liquid. Good cornmeal is a creamy white or yellow in color, never gray or dingy. It has a sweet. pleasant odor and has no trace of mustiness. It grows rancid quickly on account of its oil. It must be free from web-like bits, as these contain the larvae of insects. Keep it in a clean, dry place. Since meal does not keep as well as flour, it should be purchased in small quantities.
QUESTIONS AND PROBLEMS
In what part of this country does wheat grow? Where are the great milling centers? Where was your flour manufactured? Where was the wheat grown? Tell what you can of the manufacture of flour.
Why is wheat so well adapted to bread making? What is Graham flour? Whole wheat flour? What is their special value? What part of the grain is used in white flour? What is the difference between spring and winter wheat? Which would make the best bread flour? Why are blended wheats used for flour? Compare samples of different flours as to color, texture, odor, and the way in which they hold' their shape when pressed in the hand. What is the composition of flour? How can the starch be separated from flour? The gluten? How should flour be kept? Would you buy a quantity of flour at one time?
Why cannot cornmeal be used for yeast bread? How may cornmeal be judged? What is the difference between the new and the old process meal?
The best and most healthful bread is lightened with yeast. Yeast is a tiny plant, so small that it cannot be seen with the naked eye. It reproduces itself by budding as shown in the picture of yeast cells; that is, new cells form on the old ones, or it produces spores which may be compared to seeds. When it is planted in starchy or sugary substances it grows very fast and forms a gas from the air and from some- of the substances in which it grows. This is the same gas that was formed by the baking powder, carbon dioxide. The gas does not form as quickly in the yeast dough as it does in the baking powder bread, because several hours are needed for the growth of the yeast plant. In a mixture of flour and water and yeast kept at a temperature of from 70° to 80° F. a part of the starch of the flour is changed to sugar. This sugar then changes to alcohol and carbon dioxide, the gas that causes bread to rise. If the rising process is carried on too long so that other bacteria have a chance to grow, or, if owing to careless handling many other bacteria enter, the alcohol may be changed into an acid and the bread may become sour.
The yeast plant needs food, oxygen, warmth, and moisture just as any other plant does. The flour and sugar are its food; the water or milk gives moisture ; while the air beaten or kneaded in furnishes it oxygen. The dough must be kept warm. If all these things are supplied, and the yeast used is good it will grow just as any plant in the garden grows if it has the needed soil and climate. Think of the yeast cake as a package of tender growing plants and handle it as a box of delicate plants should be handled.
Compressed Yeast. Compressed yeast is made in the large distilleries or factories where whiskey is made. Whiskey and beer are both made by the fermentation of grains caused by the growth of yeast plants. In the distilleries the scum on the top of the vats is composed of millions of yeast cells. This scum is skimmed off, mixed with cornstarch, and formed into small cakes. These cakes are wrapped in tinfoil and kept very cold until they are sent to the housekeeper. The plants do not grow when cold but as soon as they become warm they begin to grow. Compressed yeast can be kept very cold for a short time only, as the plants die when exposed to cold for a long time. Yeast cannot be kept in a warm place because the plants grow, and after growing a while the yeast becomes sour and loses its strength. A good compressed yeast cake is of a creamy whiteness, free from dark spots or streaks, and has a pleasant odor.
Dry Yeast. A cake of compressed yeast was compared to growing plants. Dry yeast may be likened to a package of seed. If seeds are planted, more time is needed for their full growth than for the growing of young plants. Likewise dry yeast needs more time for growth than compressed yeast. It is best to start the bread at night so that the seed will have plenty of time to grow. A dry yeast cake must be soaked for half an hour before it is put into the dough..
EXPERIMENT V. Examine, under the microscope, a group of yeast cells grown in a molasses solution as in Experiment II.
EXPERIMENT VI. Dissolve three-fourths of a cake of compressed yeast in two cups of water to which one tablespoonful of sugar has been added, or use a thin mixture of sugar, water, and flour; or a mixture of molasses and water. Divide the mixture into three test tubes or flasks. Expose one to freezing temperature. Boil the contents of another tube, then cool and set away. Put the third in a warm place (about 90° F.). Dissolve the remaining yeast in a test tube half filled with pure water. Let stand for an hour, noting changes every fifteen minutes. Compare the results. At what temperature was growth most rapid l In what tube or flask was there no growth? Test for carbon dioxide, the tubes in which gas formed, with lime-water and a burning match. (See Experiments V and VI, page 197.) Do not heat the tubes. What can you say of the food and temperature required by the yeast plant? Keep the tubes in a warm place until the second day and then note odor and other conditions.
The Making of Yeast Bread. All bread recipes are based on a certain proportion of liquid to flour, the usual quantity being one cup of liquid to three or four of flour. This quantity will make one loaf of bread. Winter wheat flour takes up more liquid than spring wheat or the blended flours. The quantity of shortening or fat used, too, modifies the quantity of liquid, for shortening acts as. a liquid.
The amount of yeast required varies from one-eighth cake to two cakes, depending on the length of time allowed for rising and upon the amount of gluten in the flour. With a strong flour, that is, one rich in gluten, more yeast may be used, as the dough will stand a greater pressure of gas. One-fourth cake to each cup of liquid is satisfactory for ordinary use. For quick process bread, one-half cake should be used. Too much yeast gives a dry and porous loaf that crumbles easily. Too little yeast requires a long time for rising, and the bread may become sour because of the growth of other bacteria.
Sugar is a good food for the yeast plant and from one-half to one and one-half teaspoonfuls to one cup of liquid may be used. In making sweet breads with a large quantity of sugar it is best to use the sponge process and to add most of the sugar at the second mixing, as it may ferment in the presence of yeast and the bread become sour.
Salt is apt to retard the rising of bread, if used in large quantities. One-half teaspoonful to one cup of liquid is sufficient.
GENERAL RULES FOR BREAD MAKING
1. Scald liquids to destroy germs, and in the case of milk to prevent souring in the bread.
2. Mix hot liquids in a large bowl with sugar, salt, and shortening; cool until only lukewarm before adding yeast cake. (Lukewarm water is just a little warmer than the hand.) Be very careful in making yeast bread not to use anything hot about the yeast as the little plants are killed if the dough gets too hot.
3. Rub compressed yeast to a paste in lukewarm water. Soak dry yeast one-half hour in lukewarm water.
4. Have flour at temperature of about 70° F. If too. cold the bread will rise slowly. Do not heat it very hot if it must be warmed.
5. Warm bread pans, board, and rolling-pin (in cold weather), and mix bread in a warm room.
6. Beat batter for five minutes before it is very thick; in this way more air is beaten in and the dough will be light.
7. Put bread to rise in a warm place; a temperature of 78°F. is best for the growth of the yeast plant.
8. Knead bread thoroughly after each rising so that gas bubbles will be evenly distributed. Study kneading directions carefully.
9. Always brush the top of dough and loaves with melted fat or lukewarm water to prevent a crust from forming before the bread rises.
To Knead Bread. Flour the hands lightly and sprinkle a little flour on the dough. Use the mound of the hand at the back of the palm for kneading. Do not put the fingers into the dough. Pull the bread toward you, then push it back. Work lightly; do not press too hard or a great deal of flour will be taken up. Knead until the dough feels like velvet and comes back quickly when pressed with the finger. Bread is kneaded to incorporate air and to stretch the gluten of the flour so that the grain of the loaf will be fine.
Putting Bread to Rise. Moisten a large mixing bowl with warm water, place the ball of dough in it, brush the top with lukewarm water, and put the bowl in a pan of warm (not hot) water. Cover with a clean cloth and a pan ; put it in a warm place where no cold air can reach it until it rises to twice the size it was originally. Add a little hot water to the pan when necessary to keep it warm.
Forming into Loaves. When the bread is well risen, knead very thoroughly to distribute gas bubbles. (Be careful not to work in much flour.) Cut off a piece of suitable size and form into a loaf, place it in a greased pan, cover, and let rise in a warm place until it has doubled its bulk.