These biological processes in raw-fermented sausages constitute a rare example where microbial activity can be useful. Another example is raw fermented ham. However, this biological process can get out of control, for example if temperatures in fermentation or ripening chambers are too high or if the contaminating flora is excessively numerous with an overwhelming share of spoilage bacteria. In such cases, fermentation bacteria will not sufficiently develop and the product spoils. This risk is minimized by the use of fermentation and ripening chambers with controlled air temperature and humidity favourable for fermentation and drying (Fig. 150, 151). The second measure is the use of selected fermenting bacteria (commercially produced microbial starter cultures), which are added to the sausage mix and develop the desired fermentation processes, until moisture contents reached are low enough to stop fermentation.