Butter churn

A butter churn is a device used to convert cream into butter. This is done through a mechanical process, frequently via a pole inserted through the lid of the churn, or via a crank used to turn a rotating device inside the churn.

The agitation of the cream, caused by the mechanical motion of the device, disrupts the milk fat. The membranes that surround the fats are broken down, subsequently forming clumps known as butter grains. These butter grains, during the process of churning, fuse with each other and form larger fat globules. Air bubbles are introduced into these fat globules via the continued mechanical action of the churn. The butter grains become more dense as fat globules attach to them while the air is forced out of the mixture. This process creates a liquid known as buttermilk. With constant churning, the fat globules eventually form solid butter and separate from the buttermilk. The buttermilk is then drained off and the butter is squeezed to eliminate excess liquid and to form it into a solid mass.

The word “butter” is believed to be derived from the Greek word bou-tyron, the approximate meaning of which is “cow cheese”. However, some believe the word came from the Scythian culture, as the ancient Greeks tended to herd sheep and goats, whose milk is not as good for butter making as that of cows, which the Scythians primarily herded. The word "churn" is from the Old English ċyrin, to churn. This is probably derived from the Old English cyrnel, "kernel," due to the appearance of butter grains after milk has been churned.

The butter churn gave its name to the milk churn, early examples of which were based on butter churns. The milk churn is not, however, used for the act of churning, but rather to transport milk.

Evidence for the use of butter dates back as early as 2000 BC, and there is mention of it in biblical works. The butter churn itself may have existed as early as the 6th century AD, as can be seen by what appears to be a churn lid dating from that era. In the European tradition, the butter churn was primarily a device used by women, and the churning of butter was an essential responsibility along with other household chores. In earlier traditions of butter making, nomadic cultures placed milk in skin bags and produced butter either by shaking the bag manually, or possibly by attaching the bag to a pack animal, and producing butter simply through the movement of the animal. Some theorists believe this is how the butter creation process was discovered. Some cultures still use a process similar to this, whereby a bag is filled with milk, tied to a stick, and vigorously shaken.

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