Three Ways to Thicken Sauce (Cornstarch, Roux, Beurre Manie)

By Cook's Illustrated Published January 2019

When your sauce, gravy, or stew doesn’t turn out quite as thick as you’d hoped, you have a few options.

When your sauce, gravy, or stew doesn't turn out quite as thick as you'd hoped, you have a few options: A cornstarch slurry will create a thicker consistency, but imparts a glossy sheen that is not always wanted. A roux can also be used, but making roux takes time and a second pan. Instead, consider a beurre manié. This mixture, whose name means “kneaded butter” in French, is a paste of flour and butter that's added to hot liquid. If flour were added directly to hot liquid, it would clump; in a beurre manié, the flour particles are coated in fat, so as the butter melts, it seamlessly disperses the flour particles, which swell and thicken the liquid.

➢ To make it: Combine equal parts by volume all-purpose flour and softened unsalted butter in bowl. Using spatula or fork, mash to uniform paste. (Paste can be portioned into 1-tablespoon dollops and refrigerated for up to 2 weeks or frozen for up to 4 months.)

➢ To use it: Bring liquid to boil, then whisk in 1 tablespoon beurre manié until completely dissolved. Simmer sauce has started to thicken, 2 to 3 minutes, before adding more.

Using fork, mash equal parts softened butter and flour to uniform paste.