Addition of 3 different commercial gastric lipase preparations from goats and calves to mixed cows' and buffaloes' milk (1:1), at a rate of 12 g/100 kg milk, had no effect on milk coagulation by rennet but improved flavour development in Ras cheese throughout ripening. Cheeses made with 2 of the lipase preparations added were considered ripened after 45-60 days storage, compared with 3 months for untreated cheese milk. After 6 months lipase-treated cheeses showed no flavour defects.