Describe how butter can be prepared from milk? - QS Study
QS Study

Preparation of butter:  Butter is made by churning the cream of milk. As a result of churning, the lipid part of milk quagulates as granular substance and the liquid part get separated. To enhance the test and smell two types of bacteria are mixed with the butter. Leuconostoc citrovorum is responsible for the beautiful smell of butter. Later, this well smell butter is mixed with Streptococcusa cremoris or S lactis which fight the unwanted micro organism to restore the colour and smell of quality butter.

The enzyme of Leuconostoc bacterium converts the citrate into di-amile which offers a good tests and smell to butter.

Businessman use starter culture with the cream in order to prepare butter. In fact the starter culture contains bacteria’s mentioned above.