The fermentation vessel is ideal for fermenting milk in a low-spore environment to prepare yoghurt. Throughout the fermentation process it is important to have complete control over parameters such as pH, temperature and growth conditions in order to achieve the desired effect. The fermentation vessel consists a triple-walled, insulated, stainless-steel vat, with an overhead electrical stirring machine and a thermostat controller. The water in the triple walled machine can be heated electrically, with steam or with the central heating system.