SOFT RESINS IN SULPHURED AND UNSULPHURED HOPS. 



13 



creased in approximately the same proportion as the acid values 

 diminished. This 

 decrease in the acid 

 value and increase 

 in ester value would 

 indicate that ester- 

 ification took place 

 faster than free acids 

 were formed, the 

 original quantity of 

 free acids being prac- 

 tically used up. In 

 other words, the sul- 

 phuring of hops ap- 

 pears to hasten the 

 formation of esters 

 in the soft resins but 

 retards the forma- 

 tion of free acids. 



The acid value of 

 the soft resins from 

 the sulphured hops 

 in both cold and open 

 storage gradually in- 

 creased during the period of storage, and the corresponding ester value 



likewise gradually 

 ~^$ increased, indicating 

 that hi the unsul- 

 phured hops the for- 

 mation of free acids 

 and of the corre- 

 sponding esters goes 

 on with regularity. 



SAPONIFICATION VALUE. 



The saponification 

 value, shown in Ta- 

 ble X an d indicated 

 graphically in figure 

 5, was in this study 

 determined before 

 the ester value, al- 

 though it is usually 

 obtained by adding 

 the acid and ester values of the product under investigation. From 



y£>t/?s //v sToa^Gf 



Fig. 4. — Ester-value curves of the soft resins in sulphured and unsul- 

 phured hops in cold and in open storage. 



*S£V*W Mt STO&46£ 



Fig. 5.— Saponifieation-value curves of the soft resins in sulphured and 

 unsulphured hops in cold and in open storage. 



