Pilot scale evaluation of mash filter performance of malts with variable quality

A pilot scale Meura 2001 mash filter was used to evaluate the mash filtration performance (MFP) of malt from 13 husked malting varieties, one husked feed variety and two hulless barley varieties. The malt used in the trial exhibited a broad range of malt quality in terms of extract, fine/coarse difference, Kolbach Index, friability, wort viscosity and beta-g1ucan. MFP was assessed by the time taken for filtration (filtration time) and the total pressure required to complete sparging within approximately 60 min (sparge Pt number). The best malts required the least filtration time and pressure for sparging. All the husked malts, including the feed variety, performed at least satisfactorily with a narrow range of filtration times and sparge Pt numbers. The hulless barley malts performed poorly with long filtration times and high sparge Pt numbers. Regression analysis was applied to show that only wort pentosan content was correlated with MFP. Extract recovery was favoured by low fine/coarse difference in properly modified malts with low wort viscosity.