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 usualh 7 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 
ns " red dog." 
