Cooking In European cooking, a mixture of butter and flour called a roux is used to thicken liquids to make stews or sauces. In Asian cooking, a similar effect is obtained from a mixture of rice or corn starch and water. These techniques rely on the properties of starches to create simpler mucilaginous saccharides during cooking, which causes the familiar thickening of sauces. This thickening will break down, however, under additional heat. Types of fat include vegetable oils, animal products such as butter and lard, as well as fats from grains, including corn and flax oils. Fats are used in a
Butter Then the grains are "worked": pressed and kneaded together. When prepared manually, this is done using wooden boards called scotch hands. This consolidates the butter into a solid mass and breaks up embedded pockets of buttermilk or water into tiny droplets. Commercial butter is about 80% butterfat and 15% water; traditionally made butter may have as little as 65% fat and 30% water. Butterfat is a mixture of triglyceride, a triester derived from glycerol and three of any of several fatty acid groups. Butter becomes rancid when these chains break down into smaller components, like butyric acid and diacetyl. The