Malting and brewing trials of new barley varieties 1998-99

Abstract

Samples of three new barley varieties, the winter variety Pearl, and two spring varieties Century and Decanter have been assessed for malting and brewing quality. Each variety was compared with a control grown at the same site, namely Halcyon and Chariot respectively.

All samples were malted on a small scale using identical conditions. This allowed malting performance to be compared and also indicated the most appropriate conditions for pilot scale malting.

Each barley was then malted on the pilot scale using the conditions best suited for that variety, in order to produce a malt which was as close as possible to the pilot brewery's standard specification for ale malt.

Each malt was then brewed using identical processing conditions to produce a standard pale ale.

Barleys, malts, worts and beers were analysed using standard IOB methods. Barley endosperm quality was also assessed using the light Transflectance Meter, which is a new instrument developed at BRI as a result of HGCA-funded work (Projects 002711192A and 0054101196).

The Pearl barley was of substantially lower nitrogen, with a larger corn size and mealier endosperm quality than the Halcyon grown on the same site. Century and Decanter were similar to Chariot in barley quality. There was no evidence of a tendency to dormancy with any of the new varieties. All samples displayed some water sensitivity which is probably related to the poor weather during the 1998 growing season.

Pearl malted significantly better than the control Halcyon. (This sample of Halcyon was atypical and did not perform as well either in malting or brewing as expected with commercial samples). Brewing performance of Pearl was also better than that of the Halcyon and it gave good extract yields. However, final attenuation was slightly poorer and the yield of ethanol was a little lower than the control. There were no off-flavours associated with the Pearl beer although some taste and aroma differences were noted.

Century behaved very similarly to the control Chariot during malting and gave malts of similar quality. Brewhouse performance was also identical to that of Chariot. Fermentation was faster however.

Decanter malted well but malts displayed significantly greater protein modification, as well as higher DPs and DUs than control malts. These differences were carried through into brewing, yielding beers with higher levels of protein and colour. Brewhouse and fermentation performance were otherwise very close to those of the control. Significant flavour differences were noted, particularly on the sulphury and estery notes.