2 BULLETIN 557, U. S. DEPARTMENT OF AGRICULTURE. 



The second problem is the comparative valuation of the wheat 

 within any one class or, in other words, the relative importance of 

 factors usually considered in commercial grading. These factors, 

 briefly, are soundness, general appearance, composition, moisture 

 content, varietal differences, and impurities, especially such impuri- 

 ties as are difficult to remove. In this connection the relation of 

 such determinations as weight per bushel and average weight of 

 kernels to quality naturally forms a part of the study. 



Having these problems in mind and recognizing that the only 

 sound basis for the determination of its fitness for the manufacture 

 of flour and a study of the characteristics of the flour produced from 

 it, extensive investigations involving milling tests with wheat and 

 baking tests with the flour have been carried on for several years. 

 A partial survey of the results of this work is presented in the fol- 

 lowing pages. 



FACTORS OF IMPORTANCE IN DETERMINING THE QUALITY OF 



WHEAT. 



MILLING YIELD AND FLOUR COLOR. 



The term " milling quality " has a varied meaning, and in speaking 

 of wheat of high milling quality two millers may have very different 

 standards in mind. Broadly speaking, any wheat which will yield a 

 high percentage of white, sound flour is of good milling quality. 

 Flour yield, or the quantity of flour of good color that can be pro- 

 duced from wheat, is always the most important consideration in 

 judging wheat, Other factors are of importance in deciding the pur- 

 pose for which the flour from a certain kind of wheat is best adapted, 

 but usually play a minor part in determining values. 



Flour yield and flour color, or the color of the bread produced from 

 the flour, must always be considered together, as they are closely 

 related in their commercial significance. Yield is the quantitative 

 expression of the amount of flour that can be produced from wheat, 

 while color is the chief factor in determining the grade of the flour 

 and consequently its selling price. 



Flour yields in the following pages are expressed as a percentage 

 of straight flour. The term " straight" in this connection has much 

 the same significance as it has commercially, and includes all of the 

 flour usually included in the " Patent " and " Clear " grades. 



The color scoring system is based on an arbitrary scale on which 

 the highest markings are 105, but only very exceptional straight 

 flours score over 100. The scoring is decided upon by comparison 

 with loaves from check or standard flours. Straight flour from ordi- 

 nary sound wheat will score usually between 90 and 100. Flour 

 which will not score more than 50 is of such poor quality that it 

 would be classed with the lowest grade of commercial flours, such 

 as " red dog." 



