Hop tannin extract: a promising tool for acceleration of lautering

Abstract

Hop tannin extract (HTE), produced by ethanol extraction of hops, is a material with brewing potential. Fresh and oxidised hop tannin extracts (OHTE) made from spent hop material were tested for their ability to reduce lautering time. The filtration of wort supplemented with HTE took ~20% less time than the control wort. The active dose of HTE was between 0.5 and 1.25 mL/L of brewing water (10–25 mg of gallic acid equivalents/L). HTE accelerated filtration more than the previously used gallotannins. The efficiency of HTE was influenced by oxidation. The filtration rate of worts adjusted with OHTE increased by <15% relative to the control wort. A pilot scale experiment showed the suitability of HTE application at the beginning of mashing and the analysis of sweet worts showed that the use of HTE slightly increased foam stability, but had no effect on wort colour. The mechanism of lautering acceleration was partly revealed by filtration of Congress worts adjusted with antioxidants and haze forming polyphenols. The antioxidant properties of polyphenolic extracts played only a minor role in this effect, which is likely to be influenced by a combination of factors originating from the polyphenol composition of HTE. © 2018 The Institute of Brewing & Distilling.