The present invention relates to fermentation processes. The objective of the invention was to provide methods for producing nisin containing ferments and formulating such ferments into preservatives. It was in particular an object of the present invention to provide improved processes for producing nisin containing ferments by simple and efficient (batch) culturing and allowing for simple down-stream processing either into a liquid, semi-liquid or a dry powder product, having sufficient nisin content and stability, good handling properties and satisfactory organoleptic properties. Such processes are provided, as well as the products that can be obtained with it and their use.