Dairy products are food products made from milk. They are tasty, healthy and popular among consumers. One of the stages of the creation of dairy products is milk separation. This is the process of separating cream (fat part) and skim milk. In the past, milk separation produced by the gravitational method. For this it was necessary to put the milk in a cool place then a heavy water eventually fell down and the cream layer stayed on the surface. Nowadays, some households are still using this method.
The disadvantages of the gravitational method are obvious. First of all, the milk should stand in the fridge, taking up the space. Second, it can turn sour sooner than separated. Third, the quality of the cream is low. And fourth, it is time. Today's cream is always better to yesterdays (unless of course we do not plan to cook then butter). Therefore the necessity of special equipment for the separation of milk became apparent. And it was invented. There have appeared the machines in which the separation of milk is produced in a few minutes. Those are milk and cream separators. There are great industrial separators, which are capable of handling several tons per day. Of course, in a small economy such powerful devices are not appropriate. Therefore, over time, began to produce household milk separators, power which is just enough to serve a small farm. The performance of most current separators for milk is from fifty to eighty liters of milk per hour.
A raw for the many dairy products creates by the separation. One of the most popular dairy products is butter. Butter is made of butterfat, water, and some milk proteins. Commercial butter is 80–82 percent milk fat, 16–17 percent water, and 1–2 percent milk solids other than fat (sometimes referred to as curd). It may contain salt, added directly to the butter in concentrations of 1 to 2 percent. Unsalted butter is often referred to as «sweet” butter.
The machine for making butter by shaking cream is a butter churn. 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. Modern industrial churns are large, barrel-shaped, revolving containers in which the cream is agitated until the microscopic fat globules clump together. The liquid buttermilk is drained, and the butter is washed with sterilized water.
With butter churn the farmer’s life became easier and better.