Hardness of butter can be customised by changing the aging parameters of the cream. Cream can be aged at higher temperature with low agitation without altering the butter hardness.
Fat crystallization in cream during aging is an important process that affects churning time, texture, and mouthfeel of butter. During the aging process, liquid oil in the milk fat globules in cream start crystallizing. The amount and size of crystals in cream can be controlled by processing conditions such as crystallization temperature, cooling rate, and agitation rate.
Crystallization of milk fat in cream is essential for butter making to form a continuous fat network during churning. The crystals bind the liquid fat to their surface by adsorption.
The crystallization mechanism relevant for crystallization of milk fat is the nucleation and growth mechanism. Nucleation consists of primary and secondary nucleation. Primary nucleation can occur homogeneously or heterogeneously.
Homogeneous nucleation occurs when nuclei are formed without pre-existing crystals, whereas heterogeneous nucleation occurs when nuclei are formed by foreign substances, such as air bubbles, dirt, or a scratch on the wall. Secondary nucleation is induced by preexisting crystals.
Aging and crystallization of butter
