High-gravity brewing without adjuncts – The effect on beer parameters

Abstract

High-gravity brewing (HGB) is a common practise in industrial breweries. The aim of this study was to examine the effect of HGB on analytical and quality parameters of all-malt beer. Parameters were evaluated in bottom-fermented (BF) beer and some data were compared with results from top-fermented (TF) beer. In both, BF and TF beer, two brews were produced where a higher original gravity (OG) beer was diluted to the level of a lower OG beer. Increased ester production was the principal reason for changes in the flavour profile. Especially higher levels of acetate esters (ethyl acetate, isoamyl acetate) affected beer aroma, creating fruity and solvent-like odours. Higher alcohol and acetaldehyde contents were not affected by HGB. The use of HGB for BF beer did not affect important quality parameters such as thiobarbituric acid number (TBA) or foam stability. The content of beer ageing markers (carbonyl compounds) was also not affected by the use of the HGB technology. In sensorial evaluation, differences in flavours of BF HGB beer were evaluated in a triangle test. Beer without dilution was preferred by tasters, commenting on better harmony in bitterness and beer body.