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 alpha-amylase, proteinase and beta-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 beta-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.