How many days can fried oil last?

Cooked oil refers to cooked oil when it is poured into a pot and the temperature is high enough to start emitting a lot of smoke. Cooked oil is heated oil. Oil is cooked when it is heated to 30% to 40%. When cooking, when the oil is heated to about 70%, you can put the vegetables. If the cooking oil bought from the supermarket is heated, first, feel it by hand near the center of the pot, and second, watch the oil boil, don't wait for the pot to smoke.