CHANGES TAKING PLACE IN THE TEMPERING OF 



. WHEAT 



By E. L. Tague 

 Department of Chemistry, Kansas Agricultural Experiment Station 



In milling wheat it has been found advisable to "temper," "dampen," 

 or "condition" the grain before grinding. This process consists in add- 

 ing a certain amount of water to the wheat, then thoroughly mixing and 

 allowing it to stand for a time. The treatment toughens the bran coat 

 oi the kernel, thus making possible a closer separation of the bran and 

 the flour, and increases the desirable milling qualities of the wheat in 

 other ways. The yield of flour is increased, and a flour is obtained from 

 which better bread can be made. All practical millers are well acquainted 

 with the fact that tempering improves the milling qualil y. 



That Jago l recognizes the fact is shown by the following quotation : 



On making baking tests with the flours from such slightly dampened wheats, com- 

 pared with those of the wheats milled dry, the dampened wheat flours fall off less 

 during fermentation, yield bread of a better color and flavor, and in practically the 

 same quantity. The slight damping of very dry wheats enables the miller to pro- 

 duce a better quality of flour. 



Swanson 2 observes that conditioning not only toughens the bran of 

 the wheat and makes it easier to crush the endosperm but it also affects 

 the quality of the gluten and the baking quality of the flour. Temper- 

 ature, moisture, and time play an important part in this process. Im- 

 provement through conditioning is similar to that brought about by 

 natural ageing. 



The changes in the flour are probably either physical or chemical, or 

 more likely a combination of the two. The thorough elimination of the 

 bran gives a flour of better color, and the closer separation of the bran 

 and the endosperm produces a flour of higher gluten content. It is pos- 

 sible that the quality of the gluten is also affected. If so, this would 

 indicate a chemical change during tempering or a physical change of 

 such a nature as to make possible a more pronounced chemical change 

 during fermentation and baking. 



Since the experience of practical millers indicates that the physical 

 changes mentioned above ao occur, the subject is one which calls for 

 accurate investigation. Millers often ask the question whether the 

 obvious physical changes are accompanied by chemical changes. If so, 

 a standardization of the factors which govern the tempering of wheat 

 would lead to a more uniform product. 



1 Jago, William, and Jago, William C technology of bread making, p. 360. London, 1911. 



2 Swanson, C O. wheat conditioning. In Amer, Miller, v. 41, no. 6, p. 467-469, illus. 



Journal of Agricultural Research, Vol. XX, Nc. 4 



Washington, D. C Nov. 15, 1920 



vn Key No. Kans.-22 



(271) 



9508°— 20 3 



