IAN & SPAIN

In summer due to the high temperatures and hours of light, the storage of your olive oil is even more important. When olive oil is exposed to oxygen, light, and heat, it is subject to oxidation and may become rancid.(Go to article on how to detect oils gone bad). However proper storage can prevent this. Depending on the quality of the oil and on how it was made, extra virgin olive oil in a sealed bottle may last from 3 months to 2 years depending on the variety and the if it was filtered or not. Unfiltered olive oils should be consumed very quickly, in a question of weeks and storage of these oild is even more important. 

As soon as you open the bottle, the oxidation process accelerates and the oil will degrade fairly rapidly. Make sure you keep your oil in a closed bottle, in a dark container or closet, away from sources of heat like your stove. You do not have to refrigerate it, although refrigeration will not hurt the oil. Buying your oil in bulk is a great way to save money, as good oil can be rather expensive. If you do so, the best way to preserve it is to keep it in a stainless steel container, called a fusti. Fusti are an excellent way to preserve olive oil. For even better preservation, you can top your fusti off with inert gas from a small spray can. Inert gas prevents oxidation by blanketing the surface of the oil and displacing the oxygen, unlike vacuum systems. It is completely safe and will not affect the flavour of olive oil. "Private Preserve" is the original inert gas, and has been used by wine and olive oil lovers worldwide more many years.

If you are using a regular bulk container, try not to open it too often. Fill a couple of bottles for day-to-day use and leave the bulk container carefully closed the rest of the time.