4 
BULLETIN 1130, U. S. DEPARTMENT OF AGRICULTURE. 
(granular particles of endosperm), on the contrary, are relatively free 
from hairs and bran particles after proper purification. 
To illustrate these differences in break stocks and middlings stocks, 
a composite chart (Fig. 2) has been constructed. It is based on data 
obtained from 35 break flours and 74 middlings flours, the hair count 
being the average on all samples examined for each grade. 
The break flours in each instance show a much higher hair count 
than any of the middlings stocks. The hair count of the middlings 
stock begins to increase with the fifth middlings, indicating that the 
first four middlings are much cleaner than the succeeding ones in the 
series. 
EXAMINATION OF COMMERCIAL FLOURS. 
Commercial grades of flour generally fall into four more or less 
sharply defined classes known as "patents," "straights," "clears," 
and "low grades." As a rule the so-called 
patent flours are limited to those which are 
composed of the first-class flour streams, most 
often those ground from purified middlings 
stocks. However, stocks other than first-class 
middlings are often passed into patent flours. 
When this is the case the proportion of offal 
in the flour increases. In Figure 3 the hair 
count of patent flours made from middlings 
stocks only is compared with that of patent 
flours containing lower-grade stocks in addi- 
tion to middlings stocks. 
The average hair count on 13 samples of 
patent flours made from middlings only is 13; 
the average hair count on 13 samples of patent 
flours made from lower-grade stocks in addi- 
tion to middlings is 28. 
When only one grade of flour is manufactured 
in the mill, it is commercially designated as a 
straight flour. It usually consists of all the 
flour that can be obtained from the wheat grain 
with the exception of some low-grade flour. 
Such a flour naturally contains more offal than 
a patent flour. 
The so-called clear flours usually contain the 
lower grades of middlings and break flours, 
although they may contain the purer mid- 
dlings from the tail of the mill. Naturally, the 
offal content of such flour is higher than that of 
patent and straight flours. 
The low-grade flour is made from low-grade 
stocks, the better stocks in the mill having been 
already diverted into the higher grades. 
Table 1 shows the hair counts obtained on 
the samples of commercial flours examined. As might be expected, 
there is a variation in the counts for the different classes, doubtless 
due to the lack of uniformity in milling procedure. 
Figure 4 illustrates the differences between the four so-called com- 
mercial grades of flour, based on the average hah count obtained for 
i 
i 
I 
1 
1 
re 
i) ft 
V 
Fig. 3. — Average hair counts on 
patent flours made from mid- 
dlings only and on those made 
from middlings and lower 
grade stocks, (a) Middlings 
only; (b) middlings and lower 
grade stocks. 
