Using a thickening agent can instantly add a creamy and flavorful texture to any savory or sweet recipe. A thickening agent or thickener is a substance which can increase the viscosity of a liquid without substantially changing its other properties. What restaurants do is, they add these to the gravies and the sauces, and we get that rich texture in our food.
Here are some traditional ways of thickening sauces and gravies in the culinary industry.
Refined wheat flour cooked with the same quantity of clarified butter is referred to as roux.
3 types of roux are:
It emits an aroma of baking bread and is used for making white sauce and thickening for the cream soups.
It emits the flavour of toasted nuts and is used to make velouté sauce and can also be used in certain cream soups.
It emits a deeply roasted aroma and is used to prepare brown sauces. The darker the roux, the stronger is the flavour.
A mixture of cornstarch, potato or arrowroot, and water is referred to as slurry. It is generally used in Chinese and other Asian sauces and is added to give a shine to the sauce.
Equal amounts of butter and flour are kneaded to form a paste, which can be added to boiling liquids to thicken them.
Usually one part of egg yolk and three parts of cream and whisked together and are used to thicken the sauces. The purpose of the liaison is not only to thicken but it also enriches the sauces.
It is rarely used these days because of health reasons, but blood was a very common thickening agent used in the olden times.
Butter is also used in many sauces to provide the thickness to the sauce. Cold butter when whisked into a hot sauce gives a shine and thickness.
Starch from fruit and vegetable purees used in a dish provides the thickening to the dish and hence, require no other thickening agents.
Include these the next time you prepare a gravy and bring out that chef in you!
(Source: Food Production Operations by P.S. Bali)