Uses for the rapid viscoanalyser in a brewery.

Glennie Holmes, M.

Abstract
The "Rapid ViscoAnalyser" (RVA) measures the changing viscosity of a slurried starchy product as it is stirred at high temperature, enabling the effects of gelatinization and degradation to be evaluated. Its application to the evaluation of malt quality, for which purpose it may be regarded as a rapid laboratory mashing device, is described with reference to trials in which the effects of adding enzyme preparations and adjuncts on the mashing performance of malt were investigated. The analysis of the mash after RVA testing and the use of such analytical results as an aid to the interpretation of the RVA results are also described, using the example of two malts, both of which performed poorly in the RVA test but for different reasons; one of them showed little improvement when alpha amylase was added, indicating that it was under-modified to the extent that endosperm cell walls remained relatively intact, preventing the access of amylase to the starch, while the other improved much more, indicating that its poor performance had been caused by an insufficiency of natural enzymic activity.
Keywords : analysis equipment malt mashing measurement quality viscosity