Objective: To investigate an improvement of barley germination by application of biochar leacheate in the steeping solution for upgrading malt quality.
Results: Barley germination was improved when biochar leacheate was used in the steeping water during the first steeping cycle. A clear decrease in the time to reach 50% of final germination percentage was detected due to an addition of biochar leacheate, but no significant difference was observed in the percent germination at the end of germination. Hydrolase activities including α-amylase, proteinase and β-glucanase in barley grains were maximally increased during the malting process when 10% biochar leacheate was added to the first steeping water. The wort yielding indexes including both glucose and maltose content and the free amino nitrogen content were significantly increased but the β-glucan content was significantly decreased at a level of p < 0.05 when 10% biochar leacheate was added to the steeping water.
Conclusions: Biochar leacheate could be used as a stimulator in the steeping solution during the first steeping cycle to improve barley germination and so upgrade malt quality.
Keywords: Barley; Biochar leacheate; Germination; Hydrolase; Improvement; Malt quality.