18 



BULLETIN 557. U. S. DEPARTMENT OF AGRICULTURE. 



Table IV. — General effect of small quantities of inseparable material (other 

 grains, seeds, dirt, and chaff) on yield of flour and color of bread made from 

 hard red spring wheat of the crops of 1911, 1912, and 1913, inclusire. 



Inseparable material. 



Number 



of 

 samples. 



Flour 

 yield. 



Color of 

 bread. 



Range (per cent): 



178 

 40 

 34 



so 



Per cent. 

 71.3 

 70.7 

 69.6 



69.4 



Score. 

 94 7 



0.6 to 1 



97.1 



1.1 to 1.5 



96.1 





95.3 







FLOUR STRENGTH. 



COMPARISONS OF LOAF VOLUME. 



The term " strength " as applied to flour has been defined and its 

 significance discussed, as have also the two factors of loaf volume 

 and texture, which in this bulletin are considered as a measure of 



\SO£- tSME 



O/^ i-OS?/^ 



— cr.cr. 



S2o/ 





33 OO 



■s /o/ 



TO 



3200 



■300/ 



TO 



3 /OO 



29 O/ 



TO 



3000 



20O/ 



TO 



2900 



2TO/ 



TO 



20OO 



26 O/ 



TO 



2700 



2^0/ 



TO 



2600 



24 O/ 



TO 



2SOO 



23 O/ 



TO 



24 OO 



22 O/ 



TO 



23 OO 



2 /O/ 



TO 



2200 



200/ 



TO 



2/00 



/BO/. 



TO 



2000 



/&OZ 



TO 



/soo 



/TO/ 



TO 



/eoo 



/ffO/ 



TO 



/TOO 



/^O/ 



TO 



/GOO 



Fig. 12. — Diagram presenting a comparison of the strength of the flour (as indicated 

 by loaf volume) from the five principal classes of wheat, showing variations and 

 averages for each class. 



strength. In figure 12 a comparison is made of loaf volume deter- 

 minations of five classes of wheat, including soft white wheat, with 

 which a comparatively small number of tests were made. This dia- 

 gram is so arranged as to show the extreme and ordinary ranges for 

 each class, as well as the average, maximum, and minimum loaf 

 volume. From the data here presented it will be seen that the soft 

 white wheats are as a class lowest in strength, soft red winter coming 

 second, with durum, hard red winter, and hard red spring wheats 

 following in order of increasing loaf volume. 



The ordinary range in loaf volume for the soft wheats is from 

 1,700 to 2,200 cubic centimeters, for durum 1.800 to 2,300, for hard 

 red winter 2,000 to 2,500, and for hard red spring wheat 2,100 to 2,700 

 per 310 grams of flour. The extreme ranges in loaf volume, as indi- 

 cated by maximum and minimum, are 1,135 to 2,320 cubic centimeters 



