10 



THE PHYSICAL CHARACTERISTICS 

 OF A GOOD HOP. 



BY PROFESSOR JOHN PERCIVAL, M.A., F.L.S. 



'~PHE value of the various materials used in almost all the larger 

 industries can be, and generally is, very accurately estimated 

 where efficiency and economy are considered. The brewer has 

 found in the chemist a valuable assistant in the determination of the 

 value of many of the materials utilised in his industry. Never- 

 theless, it is noteworthy that at present no certain and accurate 

 chemical method of estimating the intrinsic brewing value of a 

 sample of hops has been established. 



Not until many more investigations have been made by the 

 brewer's chemist into the function of the hop and its constituents in 

 the brewing processes, will the more or less conventional system of 

 estimating the usefulness of a hop be superseded. 



The relative value of samples of hops, however, may be deter- 

 mined by certain physical characteristics which I propose to deal with 

 in the present communication. There is no need to enter into a dis- 

 cussion of the various chemical constituents of the hops which affect 

 the quality of beer ; it is sufficient to observe that the most important 

 of these are contained in the " lupulin glands," and it is for these 

 " lupulin glands " that the brewer should more particularly pay his 

 money when buying hops. 



These structures (sometimes spoken of as hop-meal, hop-flour, 

 pollen, or " condition ") originate as outgrowths on the small corolla 

 surrounding the "seed," and on the bracts or "petals" of the hop 

 cone. 



