Variants of Bacillus sp. no. 707 alpha-amylase are provided that are produced more efficiently and thus more economically. Higher fermentation yields are achieved through introducing amino acid variations that promote solubility of the variant in a fermentation broth. Increased solubility allows more enzyme to remain in solution after expression in a host cell. This in turn increases the efficiency with which the expressed variant enzyme can be recovered from the fermentation broth.