Thickener

Substance that can make liquids more viscous and tougher, so that they flow more slowly. There is a sliding transition between a liquid that has been thickened and a true gel, which has the properties of a solid. Thickeners are of great importance for mouthfeel and their use is, therefore, one of the most common culinary techniques for modifying the texture of a dish—for example, gravies. Eggs, starch, and gelling agents can function as thickeners. A sauce can also be thickened by adding fat—for example, butter or cream—to it when it is below the boiling point. This works because the fat in the form of smaller droplets somewhat thickens the sauce, helps to round out its taste, and makes it feel creamier in the mouth. As the fat can bind some of the taste and aroma substances, however, adding too much dilutes the taste of the gravy. Sauces of this type can also be enriched using milk, sour milk products, and cheese.