Optimisation of a Mashing Program for 100% Malted Buckwheat

Abstract

The objective of this study was to develop a temperature programmed mashing profile for 100% buckwheat malt. Both standard brewing methods and a rheological tool (Rapid Visco Analyser) were used to characterise worts and mashes. An optimal grist: liquor ratio of 1:4 was observed. At this ratio, buckwheat malt showed a gelatinisation temperature of 67°C and barley malt 62°C. A one hour stand at 65°C exhibited higher FAN levels, fermentable extracts and lower viscosity values than stands at 67°C or 69°C, and was therefore used in further mashing trials. An extra mashing step of 30 min, at any of the tested temperatures, increased extract values a minimum of 4%, decreased viscosities a minimum of 0.20 mPas, and increased fermentable extracts 12%. Best results were obtained when a mashing-in temperature was used in the range of 35°C to 45°C. These mashing-in temperatures were used to design an optimal mashing procedure: 15 min at 35°C; 15 min at 45°C; 40 min at 65°C; 30 min at 72°C; 10 min at 78°C. This program showed higher extract values and fermentable extract values (72.7% and 49.9%) than obtained by congress mashing (65.3% and 40.0%), thus successfully optimising the mashing program.