S38: The Bitter, Twisted Truth of the Hop

Hops have long been used in the brewing process for their unique bittering and other flavor/aroma properties. An important side attribute of hops has always been their natural antimicrobial properties which, together with the other analytes of beer, prevent the growth of pathogenic microorganisms and also help mitigate spoilage of alcoholic malt based beverages from, notably, gram-positive bacteria. We have, for many years, studied the various chemical components of hops to understand how we might take further advantage of their antimicrobial properties from  a brewing and non-brewing perspective. This paper describes our hop research over a period of 50 years, the detailed chemical components of hops which can usefully be used to take advantage of their antimicrobial action and the underlying mechanisms of why hops are so unique in their antimicrobial properties. We will further describe unique hop components which demonstrate antimicrobial properties at two different pH values thus steering their antimicrobial use towards either a beverage or food system, the specifics of which are provided.