Storing deep frying oil
I just bought my second deep fryer in 40 years. I got the Tfal (Emeril) model that comes apart, drains and stores the oil and most of the parts go in the dishwasher. So far, I am very pleased with it. I am wondering if I should store the canola oil in the fridge between uses. The instruction booklet says store in a cool, dry place.
Refrigerator is, IMO, the only place to store used oil. I agree that the storage container should be just large enough for the oil, without a lot of air space above the top of the oil and the cap, and if it's a clear container I'd cover it with something like aluminum foil to keep as much light out as possible. Don't forget to strain the oil very thoroughly before placing in storage. Food particles left in the oil will cause it to spoil faster.
The refrigerator is a very good place to store oil, as long as you have the room for it.
Equally as important as temperature, though, is the exposure to air. To limit the exposure to air store it in something with a very small opening at the top like a 3-liter bottle so that, once full, the exposed surface area of the oil is much smaller.
Light also causes oil to go rancid so the refrigerator is a good place to store it for this reason too.
In short, the three things that cause oil to go bad faster than it should are heat, air, and light. Keep it away from these and you'll extend the life of your cooking oil.