Cast iron is fine for deep frying fish. The smell is the real issue.

Yes, it’s safe. Cast iron retains heat well, which is key for deep frying because the oil temperature stays steady when you drop in cold fish. Just make sure you’re using enough oil – at least two inches – and that your pan is big enough to avoid splashing.

The fishy smell problem isn’t about the pan itself. It’s about the oil. That oil will absorb the fish flavor. If you reuse it for something else later, you’ll get fishy doughnuts or fishy fries. So either use an oil you’re okay tossing after one fry (peanut or canola are cheap), or keep that oil strictly for seafood batches. Label the jar.

As for the pan: clean it normally while it’s still warm. Hot water, stiff brush, maybe a little soap (yes, modern cast iron can handle a dab of mild soap – the seasoning won’t fall off). Dry thoroughly on the stove, then rub a thin layer of oil back on. No lingering smell.

Don’t let the fish smell haunt your next batch of fried chicken – Future You will not forgive that.