Bread.—Of these mixtures bread is the most important and the most difficult to make. Receipts for bread are the simplest ones we have, yet a detailed description of bread-making might easily fill a book. To read such a description for the first time would very probably shock a careful housewife. She has learned to protect her stores of food from any processes of fermentation; she regards the growth of fungus in the cellar or of mould on the back of the refrigerator as an indication of unhealthful dampness, perhaps of dirt; she probably has some terror of germs and bacteria. Is it not rather shocking then, to learn that, without fermentation, fungus and bacteria, she could not make the sweet, clean bread which she bakes every two or three days. When she has thought out these puzzling facts, she will find that each one of her bakings is a sermon from the text that all things work together for good if one knows the secret of their use.
Yeast is a form of bacteria—a germ—a microscopic fungus which floats about in the air. I find that a Government Report on the subject calls this "wild yeast." One cannot resist following out the idea thus suggested, and saying that this wild species may be caught by the housewife in mixtures of warm hops, potato and flour and "domesticated" for use in bread making.
The little yeast plants multiply quickly when they find something which they like to feed upon, and it happens that they like a mixture of flour and water which is neither very hot nor very cold. Therefore, when we put yeast into dough the little plants feed and multiply and in doing so change the character of the dough. They cause it to ferment, just as grape or apple juice ferments. When the carbohydrate substances in the flour, that is, the starches and sugars, ferment they change, and in the change form alcohol and carbon dioxide. When this performance is at its height, we put the dough into the oven, the yeast plant is killed by the heat and a stop thus put to its activities. Another result of putting the bread into the oven is that the bubbles of gas formed by fermentation expand with the heat. The gas escapes, but not before the walls of the bubbles have been hardened sufficiently by heat to make the bread full of tiny holes—"porous" we call it, and "light."
The following receipt is a usual one for a small batch of bread:
2 quarts of flour.
1 tablespoonful of salt.
1 " " sugar.
1 " " lard.
1 half cake of yeast soaked in a cup of milk.
2 cups of milk or water.
The sugar and the lard are not necessary to bread making but are frequently used; the lard because it makes bread tender and moist, the sugar to take the place of some of the sugar in the flour which is used up in fermentation.
Without the other four ingredients, flour, salt, "wetting" and yeast, we could not have bread.
The yeast is either a little compressed cake of useful bacteria, or it is a liquid in which this bacteria has congregated.
The flour is a nourishing but unattractive substance which we wish the yeast plant to change into spongy, pleasant-flavoured, digestible food.
The salt assists in making the pleasant flavour and also helps to prevent fermentation from going beyond the desired point. Unless the fermentation of bread stops at the right time, changes occur in the dough like those which take place in milk when it sours, and in cider when it turns to vinegar.