Thickening Sauces         


The quickest way is with a starch, such as cornstarch or arrowroot. Add to cold water, mix until completely dissolved, then add to sauce and stir until desired thickness is reached.

The better way, if you have time, is to simply reduce the sauce over medium-high heat, whisking to avoid burning. Cook until desired thickness, keeping in mind that flavors concentrate and become considerably stronger as water evaporates.

Alternatively, you can add either beurre manie or a roux to your sauce. Beurre manie is equal parts unsalted butter and flour, kneaded to a dense paste, and gently whisked into the sauce.

A roux is the same combination, cooked until pale gold in color, then added the same way.

The flour in these will thicken as its temperature increases, so give it a couple of minutes or more. The best rule of thumb is to go slowly. It's better to add thickeners a little bit at a time than to overthicken and attempt to dilute your sauce later.