Butter production

Delightful flavour of butter is due to about 50 different types of chemical compounds that have been identified in this product. It is the balanced quantity of various substances present in low concentrations that makes butter a particularly widely used and a major ingredient of sauces, dressings, confections, cookies, etc.

Butter is known to be one of the most highly concentrated forms of fluid milk. One should process twenty litres of whole milk to produce one kilogram of butter. This process leaves approximately 18 litres of skim milk and buttermilk, which at one time were disposed of as animal feed or waste. Today the skim portion has greatly increased in value, as it is fully utilized in other products.

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. The addition of salt to butter is sure to contribute to its flavour and also acts as a preservative. Unsalted butter often referred to as "sweet" butter should not be confused with "sweet cream" butter, which may or may not be salted. Reduced-fat, or "light" butter usually contains about 40 percent milk fat.

The colour of butter reflects the concentration of carotene, which is known as yellow, fat-soluble pigment and a precursor of vitamin A. This substance always presents in the cream from which butter is made, but the colour of cream varies with seasonal changes in the carotene content of feeds. Thus, it is deep yellow when cows graze or are fed green forage and is pale yellow when dry feeds are fed in winter. As a result butter may contain added colouring, early buttermakers having added carrot juice in winter months to increase the intensity of colour in butter. Today manufacturers add food colouring throughout the year to ensure a consistent colour. Colouring may be an extract of annatto seed or synthetic beta-carotene. As both colouring materials are oil-soluble, therefore, having been added to cream before churning, they are not lost in the buttermilk.

(Butter is commonly churned from cream, although it may be churned from milk. Butter has been found to be produced when the cream emulsion in unhomogenized milk is destabilized by agitation, or churning. Being broken the emulsion produces butterfat granules with the size of rice grains, which meet together and separate from the water phase or serum as buttermilk.

At the next step the butterfat should be washed with clean water and "worked" (kneaded) until more buttermilk separates and is removed. Finally, only about 16 percent of the water and milk solids presented in the original milk remain in the butter.

The churning process can take 40 to 60 minutes to be completed in a traditional churn, but butter is likely to be more commonly made by high-speed continuous "churns" in factories. Although the basic principle is the same, in the continuous churn cream is pumped into a cylinder and mixed by high-speed blades, forming butter granules in seconds. The butter granules are forced through perforated plates while the buttermilk is drained from the system. One can add a salt solution if salted butter is desired. Being immediately packaged, butter is known to be kept well for a long time when it is frozen.