Cheese and Yogurt

These cultured milk products differ from the other protein thickeners in that their casein proteins have already been coagulated by enzyme activity and/or acidity. They’re thus unable to develop a new thickness by being heated with a sauce. Instead, they lend their own thickness as they’re mixed into the sauce. They’re best subjected to only moderate heat, since temperatures approaching the boil can cause curdling. Yogurt is a more effective thickener if it has been drained of its watery whey. The best cheeses for thickening have a creamy consistency themselves, an indication that the protein network has been broken down into small, easily dispersed pieces; more intact casein fibers can form stringy aggregates. Most cheeses are a concentrated source of fat, emulsified droplets of which also contribute body.