

SOFT RESINS IN SULPHURED AND UNSULPHURED HOPS. 19 
The percentage of soft resins in all the samples decreased with each 
year of storage, becoming very pronounced in the third year. The 
percentage of hard resins in all the samples increased with each year 
of storage, approaching a uniform figure at the close of the third year. 
Both sulphuring and cold storage retarded the decrease in the per- 
centage of soft resins and increased the percentage of hard resins. A 
combination of the two factors was more effective in retarding these 
changes than either factor alone. 
The percentage of total resins in all the samples varied from year to 
year, and in the third year it became materially less than that of the 
original sample. The low total is probably due to the formation of 
products insoluble in the solvents used. 
The color, odor, and taste of the soft resins are of very little value 
in determining quality and are not indicative of any changes that may 
have taken ain therein. 
The acid value in general decreased in the sulphured hops in cold. 
and in open storage and increased in the unsulphured hops in cold 
and in open storage. Sulphuring apparently retards the formation 
of free acids, and a combmation of sulphuring and cold storage is 
most effective in retarding changes in free acidity. 
The ester value in anne increased in all the samples of hops. 
Sulphuring apparently favors the formation of esters, and this factor 
in combination with open storage appears to be the least effective in 
retarding the formation of esters. Nonsulphurmg and open storage 
appear to be the most effective in retarding the formation of esters. 
The saponification value in general increased in all the samples of 
hops. The unsulphured hops showed the least change, and of these 
the ones held in open storage were the least affected. 
The iodin value in general increased in all the samples. It was 
most pronounced in the second year of storage and in the third year 
was uniform in all the samples. Sulphurmg in combimation with 
open storage appears to cause a uniform rate of crease in the 1odin 
value from year to year. The sulphured hops in open storage showed 
the least variation in changes in the chemical values of the soft resins. 
During the period of storage, at least some of the components of 
the soft resms underwent rearrangement. This rearrangement was 
most marked during the first year, after which it decreased to such 
an extent that thereafter comparable values for the chemical constants 
were readily obtained. 
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