Dry, Oil, and the Flash-Rust Story
Start with the fact that actually matters: rust moves fast in dry air, and it moves faster if the pan went into a bag or a cupboard while it was even a little damp. We're at about 4,600 feet here, the air is dry, and people assume that buys them protection. It doesn't. Dry air just means a wet pan dries unevenly, and uneven drying is exactly how you get rust in patches overnight.
I learned that one the hard way, and not even at a campsite. It was my own kitchen counter.
I'd washed the oven after a cook — soap, water, all of it, which is fine, I've already said that — and I was tired, long week, so I left it sitting there wet on the counter overnight instead of drying it. Told myself I'd deal with it in the morning. By morning it had flash-rusted. Not a haze, actual rust, orange and blotchy across the whole cooking surface. Overnight, in my own house, nowhere near a canyon or a campsite.
Scrubbed it back to bare metal with steel wool and reseasoned it three times before I trusted it again. That's the story I open every class with as the don't-do-this one, because it isn't a camping mistake, it's a laundry-day mistake. It happens at home just as easily.
The actual routine
This part is boring. I won't pretend otherwise. But it's the part that separates people who own a working Dutch oven from people who own one, used it twice, and now have a rusty brick in the garage.
1. Wash it while it's still warm. Warm cast iron dries faster and the crud comes off easier. Soap and water, a scrub pad if you need it, nothing fancy.
2. Dry it with a towel, then finish it on heat. A towel gets the obvious water off, but it doesn't pull water out of the pores of the iron — cast iron isn't perfectly smooth even when it's well seasoned. Put it back on the stove or over a few coals for a few minutes until it's genuinely hot and dry. You'll often see a little steam come off after it already looks dry. That's the whole reason for this step.
3. Oil it while it's still warm. A thin layer, and I mean thin. A paper towel with a few drops of oil, wiped over the whole surface, inside and out, lid included. Then wipe most of it back off with a clean part of the towel or a second one. You want it looking almost dry, not shiny and wet. A thick layer doesn't protect better — it just goes gummy and sticky in storage, and that's its own headache.
4. Let it cool with the lid off, or cracked. Seal a warm pan up tight and you trap moisture right where you don't want it.
5. Store it somewhere it can breathe. A paper towel or a piece of newspaper between pot and lid keeps air moving and stops them developing that clingy vacuum-seal thing that traps humidity. I don't bag mine. I don't bother with the fabric Dutch oven bags people sell either — an old towel does the job if it's riding in the truck for a trip.
That's the whole routine. Wash warm, dry hot, oil thin, cool open, store loose. None of it is hard. All of it is skippable when you're tired, which is exactly when it gets skipped.
If it does rust
Don't panic, and don't throw the pan out. Rust on cast iron is a surface problem, not a structural one — unless it's gone far enough that you can feel actual pitting with a fingernail. Steel wool or a scrub pad, get it down to grey metal, wash, dry it hot, and reseason it like it's brand new — a few thin coats of oil baked on, however many passes it takes to look right again. Mine took three. That's normal for a bad case. A light haze might only take one.
One opinion while I'm here
Cleanup is the real skill in this hobby. Anybody can dump chicken and potatoes in a pan and get eight coals under it. What decides whether you're still using this oven in five years is whether you'll bother to dry and oil it on a night you don't feel like it. I mean that. The cooking is the fun part, and it's also the easy part.
Before next time
Go check whatever cast iron you've got at home right now — Dutch oven, skillet, whatever — and see whether it's actually dry or just looks dry. Any doubt at all, give it five minutes on the stove before you put it away.