Process of producing a nisin containing lactate ferment comprising the consecutive steps of: a) providing a nutrient medium comprising a solution of a fermentable substrate and a nitrogen source in an aqueous medium； b) inoculating said nutrient medium with nisin producing lactic acid bacteria； and c) incubating the inoculated nutrient medium nutrient medium under conditions favorable to the growth and/or metabolic activity of said lactic acid bacteria for a period sufficient to produce a fermentation broth containing at least 20 g/l of lactate equivalents and/or at least 1000 IU/ml of nisin equivalent activity, during which period the pH of the fermentation broth is controlled by addition of one or more alkalization agents comprising alkaline sodium and alkaline calcium salts, wherein the Na:Ca (w/w) ratio of the added salts is within the range of 1/6 - 1/2.
