Cornstarch (Best Option)
Use 1 tablespoon cornstarch per 1 tablespoon arrowroot powderCornstarch works well as a thickener because it gelatinizes at a similar temperature to arrowroot and produces a clear, shiny sauce, which is desirable in beef stew for visual appeal. It forms a smooth, stable gel that helps thicken the broth without cloudiness.
To use cornstarch effectively, mix it with a small amount of cold water to create a slurry before adding it to the hot stew to prevent clumping. Avoid prolonged boiling after adding cornstarch, as it can break down and thin out.
Compared to arrowroot, cornstarch may slightly reduce the sheen but maintains a similar mouthfeel and thickening strength, making it the best practical substitute in beef stew.