What does Thickening mean in cooking?

In cooking, thickening refers to the process of making a liquid sauce, soup, or other preparation thicker in consistency. This can be achieved through various techniques and ingredients.

1. Reduction: This is one of the simplest methods for thickening. By simmering a liquid over medium heat, the water content evaporates, leaving behind a more concentrated and thicker liquid. Reduction is commonly used for stocks, sauces, and gravies.

2. Adding Starch: Starch is a natural thickening agent found in ingredients such as flour, cornstarch, arrowroot, and tapioca. These starches absorb water and swell when heated, creating a thicker texture. They can be added as a slurry (a mixture of starch and cold liquid) or directly sprinkled into the hot liquid while stirring constantly to avoid lumps.

3. Egg Yolks: Egg yolks contain a high amount of protein and fat, which can help thicken liquids. Beating egg yolks with a small amount of cream or milk can create a rich and creamy thickening agent called a liaison. This method is commonly used in sauces like hollandaise and carbonara.

4. Dairy Products: Dairy products such as heavy cream, sour cream, and cream cheese can also be used as thickening agents. They add richness and creaminess to sauces and soups while increasing the overall thickness.

5. Béchamel Sauce: Béchamel sauce, made from a mixture of milk, flour, and butter, is a versatile thickening agent. It forms the base for many sauces, such as cheese sauce and Mornay sauce.

6. Xanthan Gum: Xanthan gum is a popular food additive made from fermented bacteria. It is a powerful thickening agent and is commonly used in gluten-free cooking and to stabilize emulsions in salad dressings and sauces.

7. Gelatin: Gelatin is derived from collagen and is a widely used thickening agent. It is commonly used in desserts, mousses, and aspic, where a jelly-like texture is desired.

Remember, when thickening liquids, it's essential to add the thickening agent gradually while stirring continuously. This helps prevent the formation of lumps and ensures a smooth and even consistency in your cooking.