86 



For the benefit of those who do not care to erect a special store, it 

 may be mentioned that the temperature of an ice cellar is quite low 

 enough to preserve hops for some time, and to prevent changes 

 in the resins. 



This brings us to a portion of our subject, closely related to 

 the employment of hops in the brewery ; and it may be pertinent to 

 ask: "Why are hops used in brewing?" Apart from the hop 

 tannin, which is said to effect a readier coagulation of the albumenoids 

 of the wort, it is particularly the hop resins that are to give the beer 

 a pleasant flavour. But in addition to this function of flavouring 

 agent, the hopping is a valuable means of increasing the stability of 

 the beer, since the hop resins influence the development of 

 bacteria. 



HAYDUCK 1 was the first to prove the antiseptic action of the 

 hop resins, in experiments made with lactic, butyric, and acetic 

 bacteria, and the Pediococcus which forms lactic acid. Subsequently, 

 RiCHARDSON 2 investigated the influence of aqueous hop decoctions 

 on certain pathogenic organisms, and in nearly every instance 

 observed a germicidal effect, and he ascribed this action mainly to the 

 hop tannin. G. HARRIS MoRRis 3 and HERON'' have also contributed 

 to this subject. ScnoNFELD 5 was the first to follow up an 

 observation of REICHARD'S G in his researches on Sarcinae. REICHARD 

 found that cask hopping of beer was an effective means of checking 

 sarcina diseases; and in consideration of this result, SCHONFELD 

 studied the influence of lupulin, and of soft resin on sarcinae in beer. 

 He concluded from his experiments that an alcoholic solution of the 

 soft resins of hops may be regarded as an intense sarcina poison, 

 and that the presence in beer of a sufficiency of dissolved soft resin 

 will retard or check the development and virulence of the 

 sarcina. 



1 Woehenschrift fur Brauerei, 1885, 268; 1888, 945. 



2 Journal of the Federated Institutes of Brewing, 1898, 128. 



3 Transactions of the Laboratory Club, 2, 26 ; 3, 24. 



4 Diary of the Brewing Room, 1899. 



5 Woehenschrift fit r Brauerei, 1898, 292 ; 1899, 665. 



6 Zeitschrift f. d. ges. Brauwesen, 1894, 265. 



