If using shrimp smaller than U 16-20, the cooking time and amount of cornstarch should be adjusted. For U 21-25 shrimp, coat with a scant 1/3 cup cornstarch and fry for 2 to 3 minutes. For U 31-40 shrimp, coat with a heaping 1/3 cup cornstarch and fry for 1 to 2 minutes.