When buying oil, to see the date of manufacture, try to buy the production date close, because the oil in the storage process will be slow oxidation.
After bought vats of oil, poured oiler them, and then immediately put the lid twist reality. Do not directly put to use when cooking for each barrel of oil, which means that every day a lot of new oxygen into oil drums.
Oiler in the amount of stored oil should be eaten within a week. Buy the best that can be screwed on the lid or a lid oiler oil bottle, do not put oil on the open mouth of the container.
Oil must be placed in a dark, cool place, do not let them be affected by sunlight and high temperatures.