114 THE CEREALS IN AMERICA 



crude fiber than the grain. The highest grades consist of 

 approximately pure endosperm, but since in producing these 

 highest grades it is necessary to reject practically all of those 

 portions of the endosperm that remain attached to the embryo 

 and to the aleurone layer, it is customary in the roller process 

 of milling to make several grades of flour with varying admix- 

 tures of portions foreign to the endosperm, in order to increase 

 the total percentage of the flour. The superiorit}' of the modern 

 methods of milling lies largely in the exactness with which the 

 various products of the wheat grain can be sorted. The almost 

 complete elimination of crude fiber in the patent flour is probably 

 one of the most important factors in affecting its commercial and 

 breadmaking value. Another rather important factor is the fine- 

 ness of the particles of flour. While flour seems like an impal- 

 pable powder, there is in reality considerable variation in the size 

 of the particles, as may be readily determined by passing flour 

 through sieves of proper dimensions. Microscopic examination 

 will show that some particles are spherical, while others are angu- 

 lar. Flour from hard wheat is generally larger and more angular 

 than that from soft wheat. The character of the milling has, of 

 course, the greatest effect upon the granulation of the flour. 

 The most desirable condition for breadmaking probably exists 

 when the flour is of medium granulation, with a mixture of 

 medium and smaller sized particles, as the capacity of the flour 

 to absorb water is thus increased.^ 



The quantity and quality of the flour therefore depend upon 

 the character of the wheat grain both physically and chemically, 

 upon its condition at the time of milling, upon the mill and upon 

 the skill of the miller. Usually seventy to seventy-two per cent 

 of the grain is made into flour, although variations ranging 

 from sixty-five to eighty per cent have been reported for differ- 

 ent varieties of wheat milled by the roller process.^ Where 



I The Northwestern Miller, Christmas, 1900, p. 20. 



* U. S Dept of Agr., Div. of Chem. BuL 4 (1884), p. 60. 



