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SOME EXPERIMENTS WITH HOPS
Author(s) -
Comrie Alan A. D.
Publication year - 1941
Publication title -
journal of the institute of brewing
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.523
H-Index - 51
eISSN - 2050-0416
pISSN - 0046-9750
DOI - 10.1002/j.2050-0416.1941.tb06094.x
Subject(s) - hop (telecommunications) , chemistry , copper , water content , fermentation , food science , moisture , humidity , relative humidity , physics , meteorology , organic chemistry , computer network , geotechnical engineering , computer science , engineering
The experiments described show that the moisture content of hops is much influenced by the humidity of the surrounding air. This influence is independent of the initial moisture content of the hop, within normal limits, and of the type of hop, but is regulated by the extent to which the air has access to the hop. Moisture determinations on hops as a means of checking the drying process are therefore of small value unless the samples have been kept in an airtight container. Variable proportions of the copper on hops are taken into solution in the wort with which they are boiled, but the amount in all cases is less than 10 per cent . of the total. There is also evidence that this amount is further diminished by the presence of copper in the unhopped wort. Contamination of wort by copper from hops is therefore not likely to be other than negligible. It is otherwise with arsenical contamination, from 50 to 100 per cent . of which is imparted to the wort. An attempt has been made to follow the changes undergone by hop resins in solution from the time the hops are added to the wort until the time the beer is in cask. Evidence of progressive and consistent diminution of the resins during boiling and fermentation has been obtained. This diminution is of the nature but not of the order of that established by the work of T. K. Walker et al . (this Journ ., 1940, 337) and the reasons for the difference are discussed. An experiment investigating the solution of hop resins during dry‐hopping of beers is described.