Q: I would like to do more deep-frying but hate throwing out all that oil. Can I reuse it?

A: If you fried something with a strong flavor, like fish, toss it. Otherwise, you can generally use deep-frying oil up to three times. Let it cool in the pan, then pour it into a container. If there's sediment in the oil (like bits of fried food), pour it through a fine-mesh strainer. Each time you fry with the oil, it will darken. Once it's two or three shades darker or starts to develop a rancid, "off" smell, discard it. (But don't pour it down the sink, because it can clog your pipes!) -- Katie

Source: rachaelraymag.com/food/your-cooking-questions-answered