Just did some deep fried food yesterday, and ended up with about 300 ml of used grapeseed oil. Normally I end up putting it in the trash, we don't have oil recycling here, at least I don't know of one. So I am thinking about using it to make HP soap for washing dishes. Have anyone done it before? The main question would: does the SAP value change after heating the oil? Any input will be very appreciated.