10 BULLETIN 493, U. S. DEPARTMENT OF AGRICULTURE, 
In Table V have been collected results (calculated from Tables 
I-IV) which show the loss in solids between the wort and the finished 
fermented product, the loss in sugar, the yield of alcohol, the loss in 
solids divided by the alcohol, and the difference between the loss in 
solids and the loss in sugar. By dividing alcohol into loss in solids 
there was secured a factor which makes possible the estimation of the 
solids in the original wort, provided that alcohol and extract are known. 
This factor also shows the yield of alcohol for a given amount of 
solids disappearing during fermentation. It has been found in the 
case of the beers that this factor averages 2.14, while in the case 
of the ales it averages 2.12, making an average for all of the prod- 
ucts of 2.13. This clearly shows that in the yield of alcohol for a 
given amount of fermentable solids there is no appreciable difference 
between top fermentation products, such as ales, and bottom fer- 
mentation products, such as beers. 
A marked difference in loss in solids is shown, however, when we 
compare the beers with the ales. In the case of the beers we find 
there is practically no difference between the loss in solids and the 
loss in sugar, while in the case of the porters and ales there is a very 
appreciable difference. The difference between the loss in solids and 
the loss in sugar is only 0.04 per cent for all of the beers; while in 
the case of the porters and ales the difference varies from 1.47 per 
cent to 2.65 per cent, with an average of 1.96 per cent. These figures 
clearly show that in the case of the porters and ales there has been 
some material other than sugar fermented. Unfortunately, the 
determination of dextrin was not made in all of the worts, so that the 
actual decrease in dextrin can be shown only in a few cases. But in 
those cases where we have the actual results the difference between 
loss in solids and the loss in sugar compares very closely with the 
actual amount of dextrin disappearing during fermentation. 
DEVELOPMENT OF ACIDS DURING FERMENTATION. 
A comparison of the amounts of volatile and fixed acids in the 
worts and in the finished beers shows that normally there is no 
appreciable development, of volatile acid during fermentation and 
only a slight increase in the fixed acid. This increase in fixed acid 
averages in the case of the beers 0.049 per cent, while in the case of 
the ales the increase averages 0.103 per cent. 
DECREASE FN PROTEIN, ASH, AND PHOSPHORIC ACID. 
A general study of the preceding tables will show that there is an 
appreciable loss of protein, ash, and phosphoric acid during #he 
fermentation. Table VI has been prepared to show the average loss 
during fermentation of the various classes of worts with respect to 
their protein, ash, and phosphoric acid contents. 
