85 



resin, which REMY 1 determined in individual cases, a quite 

 satisfactory agreement was observed. 



In view of its simplicity of execution, LINTNER'S method un- 

 doubtedly presents some advantages over the usual processes for 

 determining resins. 



The method received an interesting practical application at the 

 hands of REMY, 2 who endeavoured to judge the bittering and 

 aromatic value of hops by chemical means. REMY determined not 

 only the total quantity of bitter acids, but also the proportions of a- 

 and /3-acid, by precipitation with lead acetate ; and, as a matter of 

 fact, a certain connection was traced between the relative proportions 

 of the acids on the one hand, and the applicability of the hops on the 

 other. The results, although undoubtedly requiring further investi- 

 gation and confirmation, show that those hops, which in brewery 

 practice are employed on account of their greater bittering power, 

 uniformly contain a relatively large proportion of the a-acid ; whereas 

 with hops that are more particularly valued for mild beers, the /?-acid 

 predominates. Opinions, however, as to the value of hops, from the 

 point of view of bittering power diverge so widely, that it would be 

 rash to consider high content in a-acid either a good or bad indication. 

 For most purposes a hop showing a high percentage of total bitter 

 and a moderate proportion of the a-acid would probably be preferred. 

 In REMY'S experiments the total bitter acid ranged from 11*0 to 

 i8'5 per cent., the a-acid from 3-5 to 6*6 per cent., and the /?-acid 

 from 7*5 to 12*3 per cent. 



As has been already pointed out, the hop-resins are extra- 

 ordinarily subject to changes which detract from the value of the 

 hops ; and it will be the endeavour of every brewer to prevent as 

 much as possible these alterations, which, according to BRIANT and 

 MEACHAM,* consist in a conversion of soft into hard resin. For this 

 reason the cold storage of hops, which is strongly recommended by 

 many scientists and practical men, is a step in the right direction. 



1 Wochenschrift fur Brauerei, 1897, 513. 



2 Wochenschrift fur Brauerei, 1902, 614. 



8 Journal of the Federated Institutes of Brewing, 1897, 4^i- 



