Cornstarch

Of the purified starches, cornstarch is the most familiar. It should be used only as a last-minute thickener for sauces and cooking liquids that are being served immediately. When it is cooked for long periods, it begins to break down and lose its thickening power. Blend cornstarch with four times its volume of cold water. After 5 minutes, the slurry is ready to be used.