The cream can be supplied by a liquid milk dairy (surplus cream). From the intermediate storage tank the cream continues to pasteurization at a temperature of 95C or higher. The high temperature is needed to destroy enzymes and micro-organisms that would impair the keeping quality of the butter. The heat treatment releases strongly anti oxygenic sulphhydryl compounds, which further reduce the risk of oxidation.
Vacuum desecration can also be included in the line if the cream has an undesirable flavor or aroma, e.g. onion taste. Any flavoring will be bound in the fat and transmitted to the butter unless removed. After this the cream is returned to the pasteurizer for further treatment – heating, holding and cooling – before proceeding to the ripening tank.