WAR BREAD AND ITS CONSTITUENTS 23 



The nations of the West have adjusted themselves 

 to the eating of wheat. Its special properties have in 

 course of time determined their tastes, and they would 

 doubtless seriously suffer if in their food wheat had 

 to be largely replaced by any other cereal. Yet, 

 after all, something like three-fourths of mankind 

 dispense with wheat, and rice alone is the basal food 

 of millions of Asiatics. What would be really missed 

 by wheat-eating nations, if their special cereal were 

 to fail them, is not any special nutritive quality of 

 the grain, but the leavened bread with its light spongy 

 texture which wheat alone among cereals can yield. 



Wheat contains certain protein material known as 

 gluten, which confers special properties on the dough 

 made by mixing wheaten flour with water. When 

 yeast grows in the dough it ferments the small quan- 

 tities of sugar present, and bubbles of carbon dioxide 

 gas arise in the process. Now, because the gluten 

 makes it tough and coherent, the wheat dough retains 

 these bubbles, and during the baking the bubbles 

 first expand and are then fixed by the drying and 

 hardening of their walls, so that the bread gains its 

 characteristic light and porous structure. Flours 

 made from other cereals which are devoid of gluten, 

 when mixed with water and fermented with yeast, 

 offer no resistance to the escape of gas ; so the product 

 when baked is solid and heavy and without porosity. 

 Cereals without gluten cannot yield " loaves" in our 

 sense of the term, and wheat gains pre-eminence in 

 consequence. For the production of such loaves, 

 however, the properties of yeast are as essential as 

 the properties of wheat. It is interesting to note in 

 parenthesis, as an illustration of the way in which 

 national industries may interlock, that if distilleries 

 were closed down a possible policy, not without 

 appeal to many people the trade of the baker would 



