SOFT RESINS IN SULPHURED AND UNSULPHURED HOPS. 



Table I. — Moisture in the original samples of sulphured and unsulphured hops and in 

 samples kept in cold and in open storage. 



Treatment at the kiln. 



Original 



sample, 



1911. 



Cold storage. 



Open storage. 



1912 



1913 



1914 



1912 



1913 



1914 





Per cent. 

 6.18 

 5.23 



Per cent. 

 11.04 

 10.90 



Per cent. 

 11.04 

 10.79 



Per cent. 

 9.83 

 10.90 



Per cent. 

 5.81 

 6.14 



Per cent. 

 6.37 

 5.90 



Per cent. 

 6.40 



Unsulphured 



5,50 



From Table I it is evident that the moisture content of the hops 

 kept in cold storage was greater than of those in open storage. In 

 the samples kept in cold storage the moisture content was very 

 uniform for the three years in both the sulphured and the unsul- 

 phured hops, indicating that the cold-storage room was kept at a 

 uniform temperature throughout this period. In the open-storage 

 samples a slight fluctuation in the moisture content was evident, due 

 apparently to differences hi the atmospheric conditions at the time 

 the samples were removed for analysis. Since moisture is an impor- 

 tant adjunct to a great many chemical changes, it is probable that 

 the greater quantity found in the samples kept in cold storage had a 

 direct bearing on the chemical changes that took place in the soft 

 resins. 



SOFT RESINS. 



In determining the quantity of soft resins in the hop samples, a 

 departure was made from the method usually employed. A kilo- 

 gram of hops was extracted by maceration and percolation with 

 petroleum ether (B. P. 35° C. to 70° C). Two macerations were 

 necessary to complete the extraction. The mixed percolates were 

 then heated on a water bath at 70° C. and the major portion of the 

 petroleum ether recovered. The remainder of the petroleum ether 

 was allowed to evaporate spontaneously and the weight of the residue 

 returned as soft resins. The residues each contained a small fraction 

 of approximately 0.4 per cent of wax, which for purposes of com- 

 parison may be disregarded. The percentage of soft resins in the 

 original sulphured and unsulphured samples and in the corresponding 

 samples in cold and in open storage is shown in Table II. 



Table II. — Soft resins in the original samples of sulphured and unsulphured hops and 

 in samples kept in cold and in open storage. 



Treatment at the kiln. 



Original 



sample, 



1911. 



Cold storage. 



Open storage. 



1912 



1913 



1914 



1912 



1913 



1914 



Sulphured 



Unsulphured 



Per cent. 

 12.32 

 11.17 



Per cent. 

 11.91 



9.72 



Per cent. 

 11.46 



8.66 



Per cent. 

 4.98 

 3.81 



Per cent. 

 11.32 



8.73 



Per cent. 

 9.03 

 7.43 



Per cent. 

 3.20 

 2.32 



