How to Add Cornstarch to Sauce (Thickening a Sauce With Cornstarch)

Many Chinese recipes call for cornstarch to be added to a sauce in the final stages of cooking. However, if you don’t add it properly you’ll wind up with clumps of cornstarch instead of a smooth sauce. Here are simple instructions showing how to thicken a sauce with cornstarch.

Difficulty: Average

Time Required: 5 minutes

Here's How:

  1. Combine the cornstarch with water in a small bowl, stirring to dissolve the cornstarch (in recipes this is sometimes called a "slurry").
  1. Combine the remaining ingredients for the sauce in a separate bowl or a measuring cup.
  2. To make the sauce: move the food to the sides of the wok. Add the sauce ingredients (not the cornstarch and water) in the middle of the wok. Let heat for a few seconds.
  3. Quickly re-stir the cornstarch and water mixture.
  4. Pour the cornstarch/water mixture into the sauce.
  5. Stir the sauce quickly until it thickens.
  6. Stir to combine the sauce with the meat/poultry/seafood/tofu and vegtables.


  1. Never add cornstarch directly into the cooking liquid in the wok. Always dissolve it in water first and add the cornstarch/water mixture.
  2. During cooking, always keep the bowls with the cornstarch/water mixture and the other sauce ingredients near the stove to add when needed.
  3. Always re-stir the cornstarch slurry just before adding it to the wok.