TRANSACTIONS OF WAGNER 



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THE CHEMISTRY OF BREAD-MAKING 



Other organisms of a higher type. Carbohydrates, protein and mineral salts 

 are all essential. Just as certain constituents are necessary in soil to support 

 plant life, so are certain constituents needed in any medium supporting yeast 

 in order to develop the maximum efficiency. In the empiric method of using 

 yeast, which has been followed until very recently, it was a matter of accident 

 and not of intent whether several of these constituents were present, and it is 

 now easy to understand why bakers in certain localities would get better results 

 on account of the presence of certain constituents in the water used in the 

 preparation of the dough. Studies have recently been made of this subject 

 from the standpoint of scientific research, and Dr. Kohman, of the Mellon In- 

 stitute of Industrial Research, Pittsburgh, Pa., has recently contributed some 

 valuable facts to our knowledge of the subject. 



Among the mineral substances found to be of value are calcium chlorid, 

 ammonium chlorid, calcium sulfate, ammonium sulfate, and potassium 

 bromate. 



Certain proportions of these salts bring about a great increase in volume of 

 carbon dioxid in a given time, which is of value in enabling less yeast to be 

 used and also in shortening the time of fermentation. Other advantages are 

 lower consumption of sugar and better quality of the bread. All of the fore- 

 going substances but the potassium bromate are found usually in some amount 

 in natural waters and in other ingredients in common use. The potassium 

 bromate is a salt entirely foreign to any natural source and was employed in 

 the experiments because it is an oxidizing agent. It was found to have re- 

 markable properties as a yeast stimulant, even when used in so small a pro- 

 portion as one ounce of the bromate to 10,000 loaves of bread. This would 

 leave such a small proportion of its decomposition product (potassium bromid) 

 that a person would have to eat a whole loaf of bread each day for several years 

 to obtain the average medicinal dose of the salt. 



The results of some of these researches and investigations have leaked out 

 through the newspapers occasionally in a distorted and exaggerated form, 

 usually in the shape of allegations that the bakers are adding plaster-of-Paris, 

 sal ammoniac, etc., to their bread, and giving the impression that these are used 

 as adulterants or in large amounts, or in some other reprehensible manner. 

 The scientific and careful use of such chemicals as yeast foods is not only proper 

 and commendable, but should be encouraged in the interests of economy and 

 pubhc welfare, as they tend in every way to improve quaHty and diminish cost. 



