Butter is a food made from churning cream to separate out the solids. It is a highly concentrated milk product, taking approximately 2.5 gallons of milk to create 1 pound of butter. The by-product of the churning process is buttermilk, a thin and flavorsome liquid. Butter is a key ingredient in many recipes and is used in several cooking methods, such as baking and sautéing.
Butter adds flavor and calories to food, as it is high in fat (about 100 calories per tablespoon). Butter is solid in cold temperatures, becomes more spreadable at warmer temperatures, liquefies quickly when heated, and burns easily. It can also alter the consistency of food, for example, cookies made with butter tend to be crunchier, while those prepared with vegetable oil have a softer texture. It is the primary ingredient in several sauces such as hollandaise and bearnaise.
Butter has been around since ancient times with numerous references made to it in the Bible. 
Clarified butter is butter that has been melted until a milky residues sinks to the bottom of a saucepan, leaving a clear, yellow liquid. Once a thick white foam has been skimmed from the top and the milky residue discarded, the clarified butter is ready to be used in a variety of cooking applications. Because the milk solids have been removed, it burns less quickly than ordinary butter and can be used for sautéing delicate items such as boned and skinned chicken breasts or fish filets. Many, although not all, recipes specify its use in the preparation of brown butter sauce and of the two most famous French sauces, hollandaise sauce and bearnaise sauce. Covered tightly and refrigerated, it resolidifies and has a very long storage life.
- "...the churning of milk produces butter." Proverbs 30:33.
- Nutrition Facts and Analysis for salted butter, from NutritionData.com. Retrieved on 2009-02-05.