MILLING AND BAKING TESTS OF WHEAT. 13 



In these tests with the different impurities described there seemed 

 to be a very close relation between the effects produced on the loaf 

 volume and on the texture of the crumb. Where the volume was 

 greatly decreased, as shown in the results of the tests with corn cockle, 

 a compact loaf of bread with very small pores was obtained, while in 

 the tests with kinghcad and rye the pores were much larger and very 

 irregular in shape. Evidently the strength of the gluten was greatly 

 injured by the presence of flour from these various impurities, espe- 

 cially when added in considerable quantities, and corn cockle in large 

 amounts seemed to destroy practically all fermentation. 



Figures 5 and 6 graphically illustrate the injurious effects of rye, 

 hairy vetch, kinghcad, and corn cockle, on the milling and baking 

 qualities of straight flour made from wheat containing these impu- 

 rities. The results of the milling and baking tests in this connection 

 are given in Table IV, and the discussion of these results is given on 

 page 11. 



Plate I is a reproduction of photographs of bread baked from flour 

 obtained in milling samples of wheat which contained different per- 

 centages of rye, corn cockle, kinghead, and hairy vetch showing the 

 detrimental effects of these impurities upon the baking qualities of 

 flour. 



TESTS WITH A 10 PER CENT ADMIXTURE OF EACH IMPURITY. 



MILLING TESTS. 



Table V gives the results of milling tests with samples of wheat 

 containing 10 per cent admixtures of rye, corn cockle, kinghead, and 

 hairy-vetch seed. These samples were milled into three grades of 

 flour — patent, first clear, and second clear. The addition of 10 per 

 cent of kinghead resulted in a great reduction in the yield of total 

 flour, while there was scarcely any difference in the flour yields ob- 

 tained from the admixtures of rye and corn cockle compared with the 

 check sample of clean wheat. In this experiment but one milling test 

 was made with each admixture and with the clean wheat. In the 

 test with the 10 per cent admixture of hairy vetch, where three 

 grades of flour were made, there was an apparent increase of 1 per cent 

 of total flour over that of the check sample. Previous tests with 

 hairy vetch indicated that this impurity had little, if any, effect on the 

 flour yield, and the result of this one test with a 10 per cent admixture 

 of hairy vetch would be within the limits of variation, especially since 

 in several tests with check samples of this lot of wheat, milled as 

 straight flour in connection with other tests made hi 1913, there was 

 a range of 1.5 per cent in the flour yields ob tamed, the maximum 

 yield being 71 per cent. 



With the exception of the test with rye, the amount of patent flour 

 obtained from the samples containing impurities was noticeably less 



