Thickening agents are divided into roux and liaisons.
There are 2 types of roux:
a. Uncooked - Beurre Manie
b. Cooked - white, blond and brown.
- Beurre Manie is an uncooked roux; a mixture of butter and flour kneaded together and added to boiling liquid to thicken it just prior to serving.
- A cooked roux is a combination of fat, oil, butter or margarine and flour cooked together.
- It is used in the making of sauces and soups.
- Care must be taken during the cooking process to ensure that the flour does not burn.
- If the roux burns it will impart a bitter taste and discolour the sauce.
- A roux must be allowed to cool before any liquid is added.
- The required thickening of the basic liquid by a liaison is obtained by the addition of uncooked starches, yolks of egg, cream and blood.
- The 2 main sources of starch for thickening are grains eg corn or roots eg arrowroot, potato and cassava.