It has been demonstrated that a L(+)-lactic acid concentration as high as 162 g l(-1) can be obtained from barley starch in a relatively shout processing time of less than 48 h with a balanced simultaneous liquefaction, saccharification, and fermentation. Yields of 98 and 87% were obtained from 130 and 170 g l(-1) starch, respectively. A 10% inoculum was determined to be optimal under the experimental conditions investigated.