Butter

Butter is a dairy product made by churning cream to gather much of its fat into a semi-solid mass. The liquid separated in the process is buttermilk. Butter is a water-in-oil emulsion: small droplets of water are dispersed through a continuous phase of fat. Its texture depends on the arrangement of the fat crystals and water droplets.

Manufacture and texture

Churning breaks up fat globules in cream. Released fat gathers into grains, which grow as agitation continues and separate from the watery buttermilk. The grains are collected, kneaded and pressed together. Cultured butter develops additional flavour through the action of lactic acid bacteria, which turn lactose into organic acids and flavour compounds.

The fat contains both liquid and crystalline components. A network of crystals holds liquid fat and dispersed water within the butter. Fine crystal structures contribute to smoothness and spreadability; coarser structures can give a grainy or brittle texture. The size and distribution of water droplets also affect how the butter spreads. Cooling and mechanical working during manufacture influence these structures. Microscopy is used to examine the crystals and droplets and to relate processing conditions to the finished product's physical properties.

Types and uses

Butter is sold salted or unsalted; the quantity of added salt varies between products. Unsalted butter allows a cook to control a dish's seasoning separately. Cultured butter uses fermented cream and has a tangier flavour. Clarified butter is prepared by heating butter to remove water, then straining it.

Butter's structure gives it several roles in baking. Beating it with sugar, a process called creaming, incorporates air and helps produce a lighter texture. Its water turns to steam in a hot oven, helping separate layers in pastry. Its mixture of fat crystals also allows it to soften progressively as it warms.

History

Archaeological finds known as bog butter preserve evidence of storing fats in peat deposits, notably in Ireland. Finds have been enclosed in pottery, wooden containers, animal skins or bark. The cool, acidic conditions and limited oxygen in peat help preserve them. Their purpose is not certain in every case: proposed explanations include storage, protection of valuable food, ritual offerings and a process intended to change flavour. Chemical examination has also shown that some deposits called bog butter are animal body fats rather than dairy butter.

Margarine, invented in 1869, became a cheaper alternative to butter. In the United States, the dairy industry campaigned for taxes and restrictions on colouring margarine yellow, arguing that it could otherwise be sold as butter. By the early twentieth century, federal taxation and state bans limited the sale of coloured margarine. Some manufacturers supplied separate colouring packets for customers to mix in themselves. The federal tax ended in 1950; Wisconsin removed the last state colouring ban in 1967.

Attribution

This is an attributed adaptation of English Wikipedia's Butter, revision 1378628531, with contributor history, accessed 13 October 2026. The prose has been rewritten and condensed, sources have been independently checked, and links and structure have been reviewed for Tilcayo Cats. Available under CC BY-SA 4.0.