Indeed, so important is this ferment that, in the United States, whenever the term _bread_ is used alone it means _yeast_, or _leavened_, _bread_, whereas, when other leavening agents are used, the bread is referred to as _hot bread_, or _quick bread_, as is fully explained in another Section. It will be well to note this fact, for in all cases throughout these cookery lessons yeast, or leavened, bread is always meant when the term bread is used alone.
3. References in the history of the ancient Hebrews show that bread made light by means of fermentation was known thousands of years ago, but it was not until after the accidental discovery of the action of yeast that the making of wholesome and digestible bread became possible. Through this important advance in the making of bread came a demand for better grains and more improved methods of making flour. Indeed, so much attention has been given to these matters that at present the three important processes relating to bread-making--the raising of wheat, the milling of flour, and the manufacture of yeast--are carefully and scientifically performed. These industries, together with the commercial manufacture of bread, occupy an important place in the business of practically all civilized nations.
4. Among people who are not highly civilized, bread forms the chief article of food and often almost the entire diet, even at the present time; but as man progresses in civilization he seems to require a greater variety of food, and he accordingly devises means of getting it. Since bread is only one of the many foods he finds at his disposal, it does not assume a place of so much importance in present-day meals as it formerly did. However, it still makes up a sufficient proportion of the food of every family to warrant such careful and extensive study, as well as such mastery of the processes involved, that the housewife may present to her family only the best quality of this food.
Although it does not have such extensive use as it had in the past, bread of some description, whether in the form of loaves, biscuits, or rolls, forms a part of each meal in every household. This fact proves that, with the exception of milk, it is more frequently eaten than any other food. A food so constantly used contributes very largely to the family's health if it is properly made. However, there is possibly nothing in the whole range of domestic life that so disturbs the welfare of the entire family as an inferior quality of this food, which, besides proving detrimental to the digestion, adds materially to the household expense.