the investigation of this subject has not been always undertaken under conditions which are wholly beyond criticism. Many of the investigations have been in the interest of rival baking powder companies, and it is very desirable that this matter should be undertaken in a wholly unbiased way and conducted in such a manner as to lead to results which all will accept. Chemical and physiological investigations, which have even as a remote object the promotion of the sale of one compound and the repression of the sale of another, lose at the outset much of that claim upon the public confidence which such investigations made from a purely scientific point of view should have.
General Statement.—In respect of the use of chemical leavening agents in general it may be said that they introduce an extraneous product into the bread which is not likely to promote the health and which, therefore, on general principles should be excluded. On the other hand, large experience has shown that the consumption of bread made by these leavening agents does not produce any general effect upon the public health which is noticeable. This, it is understood, is not any valid argument in favor of the process. It must also be acknowledged that a fermentation of a bread with yeast also introduces extraneous matter into the food, viz., alcohol and congeneric products of fermentation, and hence this process may be open to a certain extent to the same objection as the one above. It is too early yet to formulate definite principles either of inclusion or exclusion of these products, and the purpose of this manual is secured when the general character and effects thereof are briefly outlined.
Composition of Bread.—Because of the many different methods of bread making which are practised it is not possible to give in a chemical form an analysis which would do more than represent in general the character of the bread in common use. For instance, the quantity of water which is found in bread varies greatly and the nature of bread itself must be influenced by the character of the flour from which it is made. The flour depends upon the quality of the wheat used in its manufacture. Hence the same brand of bread prepared in the same way and baked in the same manner must necessarily vary in composition from season to season and even from day to day. It must be understood also that it is a very common custom in the United States to use milk in the mixing of dough, and thus a food product is introduced which of itself is not of constant character. Some bakers use whole milk, others skimmed, and others sour milk.
A very good formula for mixing dough for bread making consists in using the following proportions of ingredients mentioned:
Flour, 2,000 grams
Whole milk, 500 "
Water, 650 "
Salt, 25 "
Yeast cake, 10 "
