Folks, I'm thrilled... I finally have something to contribute to this thread.
When talking about oils and rancidity, it's all about O2 and water. I have a fantastic EVOO from Israel and 3 liters from Italy.. Haven't opened either as I don't have the right tools to keep them good. Good oils will go rancid quickly when exposed to O2 and water. Funny thing is you have the same issue with your air conditioner. So we'll start there. Your AC has a compressor filled with oil. It comes packed with N2 to prevent air and water from spoiling it. One day I will own a tutsie which is an oil container that can be filled with N2. High end foodies will put their Olive or other oils in the tutsie and then spray the top with compressed N2 and close the lid. Then they'll draw the oil from the bottom of the tank. Since N2 is heavier than O2 it will protect the oil.
When talking about oils and rancidity, it's all about O2 and water. I have a fantastic EVOO from Israel and 3 liters from Italy.. Haven't opened either as I don't have the right tools to keep them good. Good oils will go rancid quickly when exposed to O2 and water. Funny thing is you have the same issue with your air conditioner. So we'll start there. Your AC has a compressor filled with oil. It comes packed with N2 to prevent air and water from spoiling it. One day I will own a tutsie which is an oil container that can be filled with N2. High end foodies will put their Olive or other oils in the tutsie and then spray the top with compressed N2 and close the lid. Then they'll draw the oil from the bottom of the tank. Since N2 is heavier than O2 it will protect the oil.