Once the relevant yoghurt culture has been added to the milk, incubation follows. The end of the incubation phase is often controlled by the pH value. As soon as the pH value reaches 4.2 to 4.5, the yoghurt must be cooled from the incubation temperature to 15 to 22 °C, to stop acidification. JUMO tecLine pH electrodes in a suitable process fitting can safely monitor this process. Once the pH value has been reached, the JUMO AQUIS pH evaluation unit controls the relevant valves to bring about immediate cooling in the plate heat exchanger.