EXERCISE XVII. 

 ' A DETAILED STUDY OF THRESHED WHEAT. 



Supplies for a Laboratory Section of Twelve. Each student should be supplied with ten or twelve two-ounce 

 samples of wheat illustrating as great a range in quality as is possible for you to obtain. Wheats raised locally, 

 and samples of must, smut, yellowberry, bleaching, etc., will add much to this study. 



Explanation and Directions. 



INTRODUCTION. To the untrained, wheat is merely wheat. The kernels have little 

 more individuality than so many shot. A little study and close observation will, however, 

 show that the individual kernels may differ greatly from one another. In precisely the same 

 manner, in a dozen or even one hundred lots of wheat, there will be found one lot as 

 superior to the others as one ball team in a locality is superior to the rest. 



To secure a sample of wheat for study, count out one hundred kernels or their equiva- 

 lent, taking kernels, impurities, etc., just as they come. In counting, two half kernels of 

 wheat should be considered as one. If trash or other foreign matter is present, include 

 it in your count just as if it were wheat. For instance, a grain of barley would be about 

 equivalent in weight to a kernel of wheat. Two or three weed seeds may in some cases 

 equal in weight a kernel of wheat and may be counted as such. For all major considera- 

 tions involving counts and a determination of per cent, divide the sample up into groups 

 which will show as many as possible of the qualities specified under the particular considera- 

 tion. Record percentage results in the proper spaces in the blank form given on page 53. 

 For example, in the study of "Naturalness of Color," divide the sample (one hundred ker- 

 "nels or the equivalent of one hundred kernels) with respect to the color of the various 

 kernels. Thus you may find present in some samples all three degrees of color, natural, 

 bleached and darkened. Record in the blank form the number or per cent of kernels present 

 in these respective divisions. 



Whenever one is studying the wheat sample for qualities which have to do only with 

 the wheat kernels and not the impurities present, as in "Naturalness of Color," it is not 

 entirely accurate to count each kernel as one per cent. The truth of this statement is 

 seen in the fact that after the wheat kernels are all sorted with respect to color, or other such 

 qualities, the total of all kernels will not usually give exactly 100 per cent because of foreign 

 matter present. Calling each kernel one per cent, however, is sufficiently accurate for our 

 purposes in this study. The quality of wheat is discussed here largely from the miller's 

 viewpoint. It is a fact that, except possibly in a few cases such as lessened quality due to 

 a little shriveling, wheat which is faulty as a milling wheat is at least as faulty for seeding 

 purposes. 



1-4. COLOR, HARDNESS, TEXTURE, AND GLUTEN CONTENT. Wheats vary 

 in color from whitish to deep red. Color, as you have observed in previous study, depends to 

 some extent upon variety and a great deal upon environment. Furthermore, you have ob- 

 served that color bears a close relation to hardness, texture, and gluten content. The darker 

 wheats in general have a higher gluten content, but where the lighter colored wheats are 

 translucent and hard (clear amber) they may have even more gluten than have most dark 

 wheats. This is best illustrated in the durum wheats grown at their best in the semi- 

 arid regions. Such wheats are of a light yellowish color (clear amber) but are of vitreous 

 texture, flinty hardness, and high .gluten content. In other words, color, which is more of 

 a superficial and external quality is apparently not so responsive to environment as are char- 

 acteristics like hardness and texture which are more closely related to internal composition. 



In hard winter wheats, "yellow berry" is particularly objectionable since it does not mill 

 as economically as it should in mills fitted for handling only hard wheats. It produces a 

 flour which lacks in whiteness and gluten content. A kernel of wheat slightly "yellow 

 berried" may show only a small pot of yellow, as seen through the cheek of the kernel, 



50 



