To thicken a sauce using cornstarch, the common guideline is:
- Use about 1 tablespoon of cornstarch per 1 cup of liquid for a thin to medium consistency suitable for soups or light sauces.
- Use 2 tablespoons of cornstarch per 1 cup of liquid if you want a thicker, gravy-like consistency
How to prepare and use cornstarch for thickening:
- First, make a slurry by mixing the cornstarch with an equal amount of cold liquid (water, stock, or wine). For example, 1 tablespoon cornstarch with 1 tablespoon cold water
- Stir the slurry until smooth with no lumps.
- Gradually whisk the slurry into the hot or simmering sauce.
- Bring the sauce to a gentle boil and simmer for about 1 minute to cook out the starchy taste and activate thickening
- Stir constantly to avoid lumps.
- If the sauce is not thick enough, add more slurry a little at a time and repeat the process until desired thickness is reached
Additional tips:
- Avoid adding cornstarch directly to hot liquid as it will clump.
- Acidic sauces (e.g., tomato-based) may reduce cornstarch’s thickening power; alternatives like arrowroot or tapioca starch work better in those cases
- Cornstarch thickened sauces have a glossy sheen and are best used fresh, as freezing can affect texture
In summary, start with 1 tablespoon cornstarch per cup of liquid, make a slurry with equal parts cold liquid, whisk into hot sauce, boil briefly, and adjust as needed for thickness.
