A butter churn is a device used to make butter from cream. It works by agitating the cream, which causes the fat molecules to clump together, separating from the liquid. This process transforms the cream into solid butter and leaves behind buttermilk. Traditionally, butter churns were made of wood and operated by hand, but modern versions can be electric. The basic principle remains the same, regardless of the design. Churning can take anywhere from a few minutes to over an hour, depending on the method and the amount of cream used.