The fat content and dry matter of the milk used in yoghurt production are standardized. Standardizing the dry matter improves the yoghurt gel. There are various ways to perform this standardization. The most common way is to increase the dry matter of the milk by evaporation in a vacuum chamber. This process is monitored by means of the temperature at inflow. The degree of evaporation is determined by the distance covered by the heated milk in the evaporator. The temperature in this process can be safely and reliably measured by fastresponding, hygienic JUMO temperature probes.