When I worked in fast food (100 years ago, it seems) we changed...
...the oil in the french fry fryers once a week. We added more fresh oil as needed during the week to keep the fryers full.
When I fry chicken strips I save the oil. I let it cool to room temp and then pass it through a coffee filter. Then I store it in a mason jar, tightly closed, in the fridge. It keeps at least 2 weeks.
I re-use the oil 2 or 3 times before tossing it.
Be careful if you fry a bunch of different things in the oil. If you fry fish, then the oil should be tossed IMO. The oil will tend to take on the flavor of whatever you fry, obviously.
Michael
