To find out if oil is the proper temperature for frying foods: For deep-fat frying, drop a cube of white bread into the hot oil. If it browns evenly in 60 seconds the oil is 350-365 degrees F., in 40 seconds, 365-382 degrees F., 20 seconds, 382-390 degrees F. For shallow frying, the oil is hot enough if it is shimmering and rippling along the bottom of the pan. The most reliable way to gauge the temperature is to use a deep-fat thermometer