Oh, another trick my Mum told me: the first time you use the oil it probably won't make the chips very crisp, but the second time is better.

Also, there is a limit to the number of times you can use the oil, so use one batch a few times, or until it looks worn out or smells a bit gluggy, and then use a whole fresh batch. Don't keep topping up the old oil with new oil.

Helen