How screwed is my cast iron?

October 21, 2013 5:09 PM

I've got mold in my skillet. Not a euphemism.

I've been sick for the past couple weeks, or else I probably would have noticed this, but apparently, my roommate took and used my cast iron skillet a couple weeks ago to cook a steak, and never bothered cleaning out the residual steak grease. So, I go to use it today, and I find that 1) it's been sitting there with fat going rancid for something like two weeks, and 2) there's mold growing on it. Great.

How much do I have to do to get this thing okay to cook with again? Simple scalding water scrub and heating on the stove to kill everything? Full teardown and reseasoning? Or will I need to pitch it and get a new one?

posted by kafziel to Food & Drink (12 answers total)

The mold will yield to a salt scrub and heating. Your roommate is a bigger problem. I don't suggest smacking him/her with the skillet though.
posted by Good Brain at 5:13 PM on October 21, 2013 [2 favorites]

Best answer: Nah. Cast iron survives just about anything. Take some boiling hot water and let it soak in the pan for about half an hour. Get a good brush and give it a good going over inside the pan. Dry it off. Throw whatever oils you normally use on it and let it heat up again on the stove for a good 15 minutes. Should be good as new. Says someone who's already done this and survived without dying.
posted by HeyAllie at 5:14 PM on October 21, 2013 [1 favorite]

I'd just take it back down to the metal (scrub with steel wool and/or salt), re-season it (put a light coating of oil in it and bake it in the oven for an hour) because it's pretty simple and you'd feel more secure. Then tell your roommate to never touch it again. If it were me, I'd be okay with a scald and scrub.
posted by jessamyn at 5:22 PM on October 21, 2013 [1 favorite]

Chuck it? Oh heaven's no. You can take rusted cast iron pans and restore them with elbow grease. I doubt mold could stand the same treatment. I'd heat it on the stove and scrub it well as if I just used it.
posted by plinth at 5:31 PM on October 21, 2013

There's a chance the molds just growing in the grease, and if that's the case, just wipe it out best you can, bring it back up to temperature and salt scrub it and hit it with some water. This will probably work just fine.

If that doesn't work, yeah, reseasoning is the order of the day.
posted by furnace.heart at 5:33 PM on October 21, 2013

What? Why would you throw away a pan just because mold is growing on the crap left in it? Mold does not grow on metal. Clean it and re-season it and you're done.
posted by oneirodynia at 5:35 PM on October 21, 2013 [4 favorites]

When I was growing up we rescued a cast-iron frying pan from the town dump, where it was covered in old cans and seagull poo. We used it constantly when I was growing up. I was at my Mum's a couple of weeks ago and I saw it sitting in her cupboard, still looking as good as when we first cleaned it about 30 years ago.
posted by AndrewStephens at 5:40 PM on October 21, 2013 [4 favorites]

About the only thing that can hurt your skillet is rust, and even that can be cleaned off if needed.
posted by jquinby at 5:41 PM on October 21, 2013

All the above are correct. I come to you only from the vantage of metallurgy and metal casting. Cast iron is funny in its crystalline structure compared to the alloys we see in other cookware. If you are expecting to heat it much over 300F then heat it as evenly as possible and cool it as evenly as possible. If heated a LOT and cooled suddenly it can crack.

So, hit it with boiling water and scrub off the residue - fine.

If you then want to heat the crap out of it to clean it (I would) - then put it in an oven at room temp. set for 500 or so for an hour, then remove after it's back to room temp.

Don't plunge it into a 500F environment nor remove it from one instantly.

Unless you want to learn to weld cast iron, that is.
posted by BrooksCooper at 10:17 PM on October 21, 2013 [1 favorite]

My long-term care habit for my cast iron is the salt scrub and dry-off, with a steel scrubber for anything stubborn. Works great, never had to reseason.
posted by rhizome at 10:42 PM on October 21, 2013

The "nuke it from orbit, just to be sure" option is the Self-clean cycle in the oven. you'll need to re-season after.
posted by ArgentCorvid at 7:37 AM on October 22, 2013

Yea, you're likely ok here.

Because oil/grease, and even subsequent mold, isn't going to hurt cast iron like water/moisture, and the subsequent rust/pitting.

Wipe/rinse the pan clean, scrub it with coarse salt and olive oil, then evaluate if you need to re-season (you may, you may not), and enjoy the pan for years to come.
posted by RolandOfEld at 10:23 AM on October 22, 2013