THE QUALITY OF WHEAT 71 



endowed with its characteristic porous structure. If a 

 cereal meal devoid of gluten is mixed with water and 

 yeast, fermentation will take place with formation of 

 gas, but the gas will escape at once and the product 

 will be solid and not porous."* 



The above quotation is sufficient to show that gluten 

 is of the greatest importance from the milling point of 

 view. It is to this gluten content that the ''strength" 

 of wheat refers. Gluten is a mixture of two substances 

 gliadin and glutenin and may be obtained in a crude 

 state from wheat meal or flour, by washing the dough, 

 made by kneading the meal with water, which removes 

 starch and other non-gluten compounds. Not only is 

 the amount of gluten important, but its quality is a very 

 potent factor in giving flour its baking qualities. This 

 quality is dependent upon the ratio of the amount of 

 gliadin to the amount of glutenin in the flour. The most 

 favourable ratio seems to be one of the former to three 

 of the latter, and, for the purpose of obtaining this ratio, 

 flours are mixed after milling, or more commonly in some 

 countries wheats are mixed before milling. A good gluten 

 has a light yellow colour, is sticky, but not elastic. This 

 difference is at once apparent if a small quantity of 

 1 1 strong ' ' Canadian wheat is masticated after one of the 

 "soft" New Zealand wheats. 



3. "Strong" and "Weak" Wheats. 



From the point of view of the gluten content wheats 

 are divided into two main classes, "strong" and "weak," 

 each marked by certain external characters, which can 

 readily be judged by the eye of the practised wheat 

 buyer. 



"Strong" wheats are usually red in colour, their skin 

 is thin and brittle and the grain is usually rather small. 



*"The Story of a Loaf of Bread," by Prof. T. B. Wood. 

 Page 36. 



