Variations in the biochemical performance of 2 DL-type mixed strain starters CH 01 and FDn grown in a sample of skimmed goat's milk I (obtained 2–3 weeks after parturition) and of goat's milk II (8 months after parturition) were studied, and results compared with those of the cultures grown in skimmed cow's milk. The initial levels of citrate differed in the 3 milks, with goat's milk II containing 0·7 mg/ml, goat's milk I 1·4 mg/ml and cow's milk 1·8 mg/ml. The production of diacetyl, α-acetolactic acid and acetoin was very low in goat's milk II. In goat's milk I the production of these compounds was higher, but still considerably lower than in cow's milk. Production of ethanol (EtOH) was similar in the 3 milks incubated with starter CH 01, but with FDn the production of EtOH was distinctly higher in goat's milk II. The total amount of CO2 produced corresponded with the initial level of citrate; consequently the highest production was found in cow's milk and the lowest in goat's milk II. The use of different starters for fermented products made from goat's milk in early and late lactation is suggested.