Cast Iron on the outdoor grill: Storing it IN the grill, lid on and covered--would it rust?

I have a not-so-weird idea but a kind-of-weird storage issue:

I do sous vide weekly and have found that searing on the grill with a propane “flame thrower” (they call it a weed burner but it’s practically a jet engine) is tops. You apply massive amounts of searing heat very quickly so you get a nice Maillard reaction without further cooking your protein much.

Recently I’ve been experimenting with just using my SO’s nice old cast iron skillet on the stove when I don’t feel like going out (or if it’s raining, like last night). I’ve been able to use various fats and oils with high smoke points (I’m looking at you, duck fat) and have been able to get unbelievably perfect seared crusts. Now–the flame thrower is fast and fun but you can’t get that kind of crust. The only issue is getting whatever fat or oil hot enough to sear in cast iron splatters absolutely everywhere and stinks up the house…sets off the smoke detector…it’s a mess. It’s a to-do.

So I’ve been thinking about getting a dedicated 12" cast iron loop-handled pan (no pan-handle) that you can get affordably pre-seasoned–put it in my grill, and grill on it instead of the grate. I could apply the torch directly down into the pan until I reach sear temps and throw in my cooking oil or fat, throw in say two steaks that will crust up real good. I could continue to apply the flame to what will end up being the bottom of the steak to sear all surfaces, pull the steaks up, flip them crust side up and serve.

The only question I have is I would want to keep/leave the the pan in the grill for storage. It would be kept with all the vents closed, the lid secured, and a water-proof grill cover bungee corded over the whole thing.

My question is: would ambient moisture cause it to rust even tho it’s covered by both a lid and a cover?

Is there something that could be done to prevent oxidation, such as spritzing it with oil after every use?

It might sound silly, but I really have few other storage options for such a dedicated piece of hardware. We have a very large cast iron pan to use inside that lives in the oven unless we need to bake something, then it goes on the stove top. We have a dearth of cabinet space due to a the dumb layout of our kitchen.

I’d be more worried about residual fats/oils/food bits attracting rodents more than rust. Of course, where your grill is situated matters a lot too.

Interesting perspective–when I grill/sear on the grate, there’s always fatty meat bits left over that I have to super-heat and clean off with a grill brush before my next sear. So far I have never encountered any varmints nibbling on them.

I’d be impressed by any that can climb up a Weber Kettle and wiggle their way under the bungee-corded lid. I’m not sure it’s possible for them to get in.

The grill is kept on the back patio near the door.

Rodents can absolutely get in, don’t even fool yourself they can’t. And if you use it weekly without fail it probably won’t rust too much especially if you’re in a not terribly wet climate.

How?

And can you prevent it?

I’ve been battling a rat problem and the little motherfuckers can get through gaps you’d swear you couldn’t pass a piece of paper through–it’s possible I’ve got some rodent inspired PTSD going on. On the plus side, there’s not much in a BBQ they can mess up and the heat will sterilize everything so there’s that.

The cast iron skillets at the deer camp rust every year. They just clean them up and reseason. Of course that means they are left to their own devices a good 10 months. No amount of oil, fat, or lard stops it.

I think if you use your grill/skillet arrangement often you’ll be ok. Just check before each use.

Never mind rats…mice can enter even smaller holes. Some BBQ units I have seen have vent holes that wouldn’t be a problem for small mice.

Just make sure they can’t exit. That way, you will have a container of (probably desiccated) roast-able corpses ready for you in the spring. :slight_smile:

Bonus: I understand their tiny bones can be used as toothpicks.

I’m fairly new to cast iron, but my understanding is, shocked cast iron WILL crack, so if you leave it outside in the cold and then apply a blow torch to it, the fast change in temp might be a hazard to your pan.

Would torching the cast iron after cooking help keep it from rusting? Give it a wipe to get rid of most of the gunk and rub the whole pan so it’s covered in the residual fat. Then torch the pan to re-season it. The basic process of seasoning a pan is to coat it in oil and get it really hot, so maybe torching it after each use would do the same thing. Hopefully a cast iron expert can weigh in if that would be viable.

I’d be happy they’re doing some cleanup work for me. How often does anyone get to do that Disney princess thing where wildlife assists with chores?

Sheesh, the mice wanna clean up your mess for you? I say, let 'em.

Yeah, the mice can get into some pretty tight holes. When I worked at a chemical plant we worked 24- 7 so there was always coffee on. Some people didn’t want to take the time to close the top of the non-dairy creamer, I have seen a mouse go into the can. The hole is smaller than the diameter of my little finger.:eek:

All this speculation that mice can somehow get into my closed grill is kind of not the point and a complete non-factor in my decision making process. You mentioned vents–all mine are closed. I have a Weber Kettle that has hard-to-open vents that I always keep closed since I only use the grill to sear sous vide meats and not for actual grilling. We have issues with wind/rain so I have have a waterproof cover that I bungee cord all the way around then top to bottom to prevent it from coming off in any way. So there’s extra down-force to the lid.

If anything larger than say a flea can wiggle their way under the lipped lid which is held down with more force than just the weight of itself then we’re all doomed and that creature will eventually rule this planet. Ability to get in is the last thing we need to worry about. And if a liquefied mouse can Terminator 2 their way into sluicing through the millimeter gap between the closed vents, then there’s nothing anyone can do to stop them and the planet belongs to them. So all of your worries are apocalyptic.

In real life, I’ve gone weeks with chunks of meat left on the grates without any issues. So I’m going to just bypass all this rodent problem stuff when it comes to leftover vegetable oil left in to season a cast iron pan. At any conceivable rate, they won’t LICK IT PURE CLEAN, but if they manage to, I can just get it hell-ass-hot and re-season it.

MOVING ON FROM MICE…

  1. Thermal shock is not an issue. Due to the fact that every year is the newest hottest year on record, we get below freezing maybe a few nights a year. Doing some research, bringing the pan to heat slowly won’t take much longer than going nuts-fire on it. A lot of people talk about throwing their hot pans in cold water, which I’d never do, with no cracks. This is like the liquid mice—not an issue.

  2. I have a shed I could keep it in, but I think it’s less secure (to T2 Liquid Alloy Mice) than the actual grill, bigger space, on a shelf, would have to wait for it to cool down, big hassle, no climate control, and would probably be more susceptible to ambient moisture than the closed vent, lidded and covered 22" grill.

  3. It would get at least bi-weekly use, if not weekly.

  4. I’m already pretty well convinced that it’s worth a $20 experiment at this point. If the mice over-rule then I know which of you I need to commune with so we can start a fort to at least TRY to continue on the human race, even if we (would at that point know) it’s futile. Other than that, I know if the thing starts to rust I can recondition and reseason it and try again. I can try other junk, like letting it cool and covering it in foil or plastic wrap, or whatever else. But I don’t think I’m in danger of ruining the pan or my grill, just the entire human race because of nano-gel rodents who drink canola oil like vampires crave blood. Which, again…much bigger issue.

I’ve had grills with cast iron grates before and I don’t remember having a rust problem.

I sometimes see cast iron pans at thrift stores. If you don’t want to risk your good cast iron to this, you can probably find a sacrifice pan.

You mentioned storage space issues in the house. I’ve heard of some people storing their pan in the bottom of their oven–on the inside.

Unless you live in very humid area, you’ll be fine with leaving the pan in the grill. I have a couple of cast iron dutch ovens for camping and I leave them in the garage (covered in a cloth bag) with the rest of the camping gear. Just make sure to clean, thoroughly dry and lightly oil after every use.

If it is seasoned enough to be non-stick, would it be seasoned enough not to rust? I don’t know.

And I am afraid to find out. If I left the cast iron skillet outside and it rusted, I suspect I would find out from the Lovely and Talented Mrs. Shodan if the seasoning helped it fit up my left nostril.

Kidding. Probably.

Regards,
Shodan

Pacific NW here. I’ve tried storing various items in the grill outside. Anything that can rust, will rust, due to the constant humid air condensing on cold surfaces.

Even worse, anything that can become a sticky webby home for large fast spiders will become a home for them. Upon seeing the multiple funnel webs covering my pristinely stored bundle of kebab skewers, I noped out of a whole summer of kebabing.

The problem I’d have with torching after cooking, is that that’s when I’d prefer to be eating my steak, or relaxing after eating my steak.

I’d give it a try with a sacrificial cast iron pan. I feel the OP’s pain.

That’s the real issue- if it’s humid enough, water will condense out of the air onto the cast iron in the mornings, eventually causing rust.

Unless you live in the desert, in which case it’s not liable to happen. But most other places would still have that problem at some point of the year, I’d think.

Beyond that, wouldn’t you still want to take your cast iron pan in to clean it after use? Why not just keep it there?

It will rust - more so after being exposed to high heat. I guess it burns off the seasoning. It won’t rust quickly, though, so if you’re using it frequently, you can go a while before having to deal with it. Seasoning cast iron is easy. Dealing with rust is too: light sanding, then season.