A STUDY OF AMERICAN BEERS AND A] 



9 



A study of these tables shows very clearly that during fermenta- 

 tion marked changes are brought about other than the mere con- 

 version of sugar into alcohol. While it is well known that th< 

 changes take place it seems worth while to consider them hi 

 because no similar study relating to American brewery products has. 

 been published. Further since we have the exact analysis of 

 wort and of the beer which was made from it, we have a special oppor 

 tunity to examine quantitatively some of these changes, such as th< 

 production of alcohol, the fermentation of dextrin, the development 

 of acids, and the losses of protein, ash, and phosphoric acid duri 

 fermentation. 



In order to study the question of the yield of alcohol, to test the 

 present factor used for the calculation of the solids in the original 

 wort, and to show the approximate amount of dextrin, calculatio 

 were made, the results of which are presented in Table V. 



Table V. — Changes taking place in the conversion of worts into beers and ales. 



Product. 



Loss in 

 solids. 



Loss in 

 sugar. 



Alcohol. 



Loss in 

 solids 

 divided 



by 

 alcohol. 



Differ- 

 ence 

 between 

 loss in 

 solids 

 and loss 

 in sugar. 





Grams 

 per 100 cc. 

 8.59 

 8. 55 

 8.27 

 8.48 

 8.02 

 7.27 

 7.53 

 7.35 

 7.07 

 6.04 

 5.86 



Grams 

 per 100 cc. 

 8.45 

 8.43 

 8.49 

 8.27 

 7.99 

 7.42 

 7.73 

 7.46 

 7.13 

 6.05 

 6.01 



Grams 

 per 100 cc. 

 3.85 

 3.91 

 3. 83 

 3.72 

 3.66 

 3.45 

 3.33 

 3. 31 

 3. IS 

 3.02 

 2.87 



2.23 

 2.18 

 2.13 

 2.27 

 2.19 

 2.10 

 2.00 

 2.22 

 2.22 

 2.00 

 2.04 



Gravis 

 per 100 cc. 

 II. 14 



Do 



.12 



Do ... 



.22 



Do . . 



.21 



Do 



.a - ? 





. 15 



Do 



.20 





.11 



Do 



Beer (all-malt) 



.OK 

 .01 



Do . . . 



. 15 















2.14 



.04 













Porter (small) 



9.23 

 9.91 

 10.06 

 9.90 

 10.31 

 10.63 

 10.70 

 11.15 

 11.50 

 11.62 

 11.04 

 11. 8S 

 11.75 

 12.03 



7. (ill 

 8.32 

 8.27 

 7.82 

 S.84 

 8.98 

 -9.20 

 8.94 

 9.57 

 9.06 

 9.50 

 9.63 

 9.11 

 9.38 



4.30 

 4.70 

 4.75 

 4.72 

 4.82 

 5.11 

 4.93 

 5.16 

 5.34 

 5.35 

 5.43 

 5. 67 

 5.53 

 5.69 



2.14 

 2.10 

 2.11 

 2.09 

 2.13 

 2.08 

 .2.17 

 2.15 

 2.15 

 2.17 

 2.03 

 2,09 

 2.12 

 2.11 



1. Cv! 



Porter (large) 



1.59 



Do 



1.79 



Do 



2. OS 



Ale 



1.47 



Do 



Do 



1.65 

 1.50 



Do 



2.21 



Do 



1.93 



Do 



2.56 



Pale ale 



1.54 



Do 



2.25 



Do 



2.64 



Brown stout' 



2.65 







Average for ales 









2.12 

 2.13 



1.96 























65991°— Bull. 493—17- 



