Butter is made by beating cream, the thickest, fattiest part of milk. As it is beaten, the fat globules begin to stick together, forcing the cream to form a solid mass of milkfat, also known as butter. Although many people are taught to refrain from consuming fatty products, pure butter without additives contains healthy fatty acids, which benefit cholesterol levels and general health. While an excess can be harmful, the food is not inherently bad for you.
There are two types of butter: traditionally made, which uses soured milk, and fresh. Traditional forms are sometimes labeled as “European Butter” in stores, and you may have noticed that it has a rich, slightly sour, intense flavor. Butter made with fresh cream is much more mild. It also comes in salted and unsalted formats. Traditionally, butter was heavily salted to keep it from going rancid. It is more lightly salted today that it was historically, so that the salty flavor does not dominate. Unsalted is also available for certain cooking applications.
When butter is made traditionally in a dairy, vats of milk are set out after milking in a cool place so that the cream can rise to the top. The top of the milk is skimmed, and the cream is collected in a large container for up to a week, so that a large batch can be made. The cream is also allowed to sour slightly, forming acids which help to break down the fat in the cream. Next, the cream is poured into a churn to be beaten. In an upright churn, a paddle is pounded back and forth. Other churns use a rotating motion. Either way, constant speed has to be kept up as the butter forms, leaving watery buttermilk behind.
The buttermilk is poured off, and the butter is worked with cold water to remove the last of the buttermilk. Next, it is salted and packaged for sale. Modern butters made in this style are usually made with milk which has been cultured with yogurt, so that the final product has a dependably tangy flavor. This also reduces the risk of food borne illness which is increased by leaving dairy products out at room temperature to sour. However, many dairies choose not to culture their cream, and instead simply whip fresh cream at a high speed.
Making butter at home is easy to do, and it can be a fun activity. Start with high quality fresh cream that has no additives. Some consumers choose raw cream which has not been pasteurized, as they feel it performs better. Put the cream into a mixer and run it at high speed until the buttermilk separates out. Pour the milk off and work the butter with cold water to wash it, before adding salt or flavorings of your choice.
You can also make butter by shaking cream in a jar, if you have the patience; it can take up to an hour, and you need to be conscientious about keeping the cream cold. The buttermilk can be used in cooking or drunk plain, and it has an interesting flavor which many people enjoy. For a more soured flavor, add cultured buttermilk from the store to the cream and allow it to sit at room temperature overnight before beating.