PRODUCTION OF BUTTER
Whole milk is transported from the farm by means of refrigerated trucks in the special tanks to a dairy plant, where it is skimmed, separating the cream from the rest of milk. Then the cream is ripened to increase its acidity. For ripening, cultures of lactic-acid-producing bacteria are added to the cream.
Pasteurization. Before it is churned into butter, the cream is first pasteurized. Most often, pasteurization is accomplished by heating the cream to 163 F˚ (73˚ C) for 30 minutes. However, another method, known as high temperature-short time pasteurization (HTST) is also widely used. In this method, the cream is heated to at least 180˚ F (about 82˚ C) for a minimum of 16 seconds.
After pasteurization, the cream is cooled to about 40˚F (about 4˚ C) and held for churning. The temperature of the cream at churning time is important if churning to be successful.
Churning. In most modern dairy plants, the butter churn is a huge rotating cylinder or drum with shelves inside that serve to raise and drop the cream as it is being rotated. After the cream is agitated in the churn for about 40 to 45 minutes, it becomes a foamy mass. The butter then forms as small granules, each granule consisting of an air bubble, surrounded by fat globules. When the air bubbles collapse because of increasing weight of granule formation, the “breaking point” is reached. The moment this happens, a glass observation window in the churn clears, and the operator sees the butter granules floating on the surface of the remaining liquid, the buttermilk. After the granules have become the size of small peas, the buttermilk is drained off, and the butter then is washed, salted, and worked.
Modern cylindrical or barrel churns are capable of producing as many as 5,000 pounds (2,267 kg) of butter in 1 hour. Early churns, which could produce only about 500 pounds (227 kg) of butter at one time, were made of wood and were so porous that they were difficult to sterilize. Modern churns are made of metal and are easily cleaned.
Working of butter. After washing, the butter remains in the churn and is worked. The working of butter is essentially a kneading process, similar to the kneading of bread dough. In this process, the butter granules are worked together into a soft mass. It is also at this time that coloring matter and salt (if desired) are added and worked smoothly through the mass. High quality butter has good body texture and is not “leaky”. Leaky butter does not retain its moisture very well.
Final steps. The finished butter is packed in parchment-lined corrugated or fiber boxes. Later, converters repackage the butter into smaller units – generally patties, 1 pound (0,45 kg) packages, and ¼ pound (114 gm) sticks. Before it is wrapped, each batch is assigned a grade.
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