Page "Cooking" Paragraph 17

An emulsion of starch with fat or water can, when gently heated, provide thickening to the dish being cooked.

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.