How to Clean a Cast Iron Frying Pan and Season It Afterwards

How it started

I'll never forget my days as a dishwasher at a busy café. The pace was crazy. Every so often, I'd be handed a scorching hot pan caked with grease. With no time to think, I'd grab the steel wool and splash the pan with water to cool it. I thought I was doing my job right.

No one corrected me, so I carried on. But something didn't feel right. I knew in my gut this wasn't real pan care. After all, how could splashing cold water into a hot pan be correct?

Years later, it all clicked - why the pans were so hot, why they kept rusting, and why the café owner seemed unfazed. Turns out, I was cleaning these cast-iron pans right — at the time. Reality was, with quick café turnarounds, there just wasn't time for 'correctness'.

I've learnt all the cast-iron cleaning quirks since. And now, I want to share them so that you won't be as confused as I was.

Some common myths I want to dispel

• "Rust on the pan means it's got to go." False. Rust is fixable. It happens if moisture isn't cleaned or the bare iron is exposed when it's humid.
• "Steel wool mustn't be used." False. It’s great for removing rust, but you just have to know the seasoning layer will take a hit. And I don't mean seasoning as in salt and pepper. Seasoning means oiling your pan, and baking those oils so that they form a protective layer. This layer is also known as patina. We'll get into the chemistry of this later on.

• "Dish soap is bad, never use it." I’ve got my own take on this, as I know exactly what’s in my product. People say this because old soaps used a corrosive thing called lye. Lye strips the seasoning we create and exposes the iron. Modern dish soaps don’t use lye anymore, so many folks think they’re fine. But most still have SLS or SLES, which are strong degreasers. Sure, they’re milder, but they’ll still affect seasoning over time. My view is to use dish soap if you need to, but make it quick. Scrub, rinse, and don't soak in it unless you're planning to reseason.

Deep cleaning your cast-iron pan after use

Have these things handy:

• Kosher salt or any coarse salt e.g. sea salt (large crystals work better as they're more abrasive).
• Chain mail scrubber - Like the name suggests, it literally looks like chain mail medieval armour. It's available at Big W or a bit cheaper on Amazon.
• Two dish cloths - one to scrub, one to dry.
• Rubber gloves
• Dish liquid - preferably a natural cleaner. Warm water, dish liquid, and a scrubbing pad/dish brush are all you need for light cleans.
• Cooking oil - Any general one works.
• A silicone-tipped brush
• Paper towels

Step 1: Cool the pan down

Set it somewhere safe, and let it cool naturally. The problem with cooling it with water, like me in the café, is that there's a chance the pan just cracks. I know it's tough and not super likely, but there's no need to shock such a hot pan, especially if it's been in the oven.

Step 2: Use salt or chain mail depending on its state

For everyday stuck-on food, use Kosher salt. Tip out what you can first, and apply the salt generously. If your pan has dried or rusted, go straight for the chain mail instead. Steel wool works if you want a quick way out, but understand it'll strip off more than the others.

Step 3: Scrub until there's a smooth surface and all debris is gone

If you're using salt, get a new batch on once it starts browning. Use a clean, dry dish cloth to massage the salt around. Vigorous circular motions are what we want. The reason this works is because salt is mildly abrasive. This means it'll clear debris without affecting seasoning. Work the pan with your scrubber if food is too cooked-in. Just know that with chain mail, it too will bring the pan close to bare bones, so seasoning after is still needed.

Step 4: Make use of the stove

It helps to do all this over heat, especially if things get difficult. Heat just loosens residue and stuck-on food. Unlike nonstick pans, there's no need to hold back with metal utensils. So you can even scrape the surface with a metal spatula. If all else fails, add boiling water. Allow the water and the pan to cool before you start cleaning. Then try scrubbing from there.

Step 5: Discard the salt, rinse, and dry

Our company is all for reusability, but not here. Get rid of the salt (don't cook with it) and rinse the pan off. If you're using our cleaner, you should dilute it because it's slightly alkaline. The higher pH you get to, the more likely it affects seasoning. Not going to get into why, but either way, there's no need to soak the pan ever. Whatever you're using, get it on and off as quick as you can, and towel dry. For regular dish liquid, I still suggest gloves since those products aren't very healthy.

The science behind seasoning (and why it matters)

Knowing the basic science behind your pans ensures proper care. This is everything from daily habits to choosing oils in the shop. You’ve heard me say “seasoning” a lot, so let's dig deeper. When you heat oiled up cast-iron pans, a process called polymerisation happens. In simple terms, the heat causes the oil’s fat molecules to bond to the iron and connect with each other. What you get is a water and stick-resistant plastic-like coating. This makes cooking and cleaning easier and keeps the pan rust-free. You’ll be psyched to know that normal cooking with oil also adds to this layer. This is especially true with fatty meats and high-heat cooks. Still though, seasoning every so often will keep the pan optimal.

So how do you actually season?

Like how I use a silicone brush for non-stick pans, the same brush can be used for cast-iron. But what oils work best? It's counterintuitive, but the more unsaturated the fat is, the better. It all has to do with chemical compositions. Oils like lard might seem like they'll be efficient coatings, but they don’t polymerise well. The reason is that they lack enough double bonds between their fat molecules. Unsaturated oils like canola have more of these bonds, which help them hold tightly to the iron. When they're heated, what you're left with is a strong and smooth seasoning.

The catch

Some people suggest flaxseed oil since it's one of the most unsaturated fats. The issue is, if the fat is too unsaturated, polymerisation gets too efficient. Oils like flaxseed polymerise fast, but they're prone to flaking and brittleness. The pan needs to be utterly clean and dry if you want flaxseed oil to work. Use everyday oils like vegetable, canola, or grapeseed to make things easier.

Step 1: Grease the pan up

Some people like heating their pan up first. And yes, you can eliminate moisture and get a more even spread. I personally don't do this. The reason is, skillets can weigh quite a bit, which adds a burn hazard if the pan is mishandled. I know it can work, but I just like playing it safe. Anyways, oil the pan inside and out using a silicone brush or a folded paper towel. Apply some pressure so that the pores consume the fats. You want a thin, even layer such that no area is visibly greasy. I like to get around the handles and underneath the skillet too. This is so that every part of the pan is shielded from rust.

Step 2: Preheat the oven to 180°C

This is critical since you're aiming for even polymerisation. If you skip this, you may get brown spots that look like caramelised sugar. This is a sign the oil wasn't polymerised, and you'll need to start over again with salt. I like 180° because many oils have smoke points around 200°C. When oils exceed their smoke points, they can break down, release toxins, and disrupt our process. So I just like having this conservative buffer.

Step 3: Stick the pan in for 1 hour

Make sure the pan is upside down and has no moisture going in. Oil and water don't mix, so what you can get is jagged lines and uneven coating. Under some pans, there are also branding ridges sticking out. Gaps of the letters can gather oil and cause unevenness too. An upside down pan lets oil flow downward with gravity. This means as it cooks, you get nicely oiled sides that are also well coated. Speaking of gravity, dripping is guaranteed. So either pop your pan on an oven tray or place foil on the racks below.

Step 4: Let the pan cool and feel it

A well seasoned pan shouldn't feel sticky. It should feel smooth and look black and shiny. At the café, I was never able to feel what a proper pan was like. It was always pitted, had hot spots, and was rough to the touch. This shouldn't be the case with freshly seasoned pans. If it passes your 'feel-test', give it a thin oiling, and store it in a dry place. Then, rest the pan on some paper towels. Too much oil in the layer can make it go rancid, so only use a light touch. If you're storing things above the pan, lay paper towels between for hygiene.

Frequently Asked Questions

How often should you reseason your pan?

New pans often come preseasoned, so that gives you a time buffer. But from there, anytime your pan starts underperforming. For example, if food starts sticking, or you see the pan getting dull. There's no "optimal" frequency as everyone uses their pan differently. You should reseason whenever you feel resistance cooking with it.

What is the best way to remove rust?

This is an unpopular opinion, but I'm firm on using steel wool. Hear me out. If your pan is already at rusting point, chances are you need to reseason anyway. Steel wool will grind it to its iron surface, giving you a clean slate. Once it's scoured, follow the steps we covered above.

What causes rusting to begin with?

Mainly moisture. Rust forms when iron reacts with water and oxygen. This creates iron oxide, which is basically rust. Unlike stainless steel pans, cast-iron doesn't have a rust-proof barrier. Some guides encourage storing the pan in the oven to utilise residual heat. This makes sense in theory, but those guides don't factor in condensation, which can cause rust. In the case of storage, hanging them or using paper towels makes the most sense.

Dishwashers yay or nay?

They will work, but expect rust spots on the pan and on surrounding dishes. That rust can transfer and stain other items in the load. With dishwashers, water and soaping agents blast at the pan repeatedly. So you have to look at them as an equivalent to soaking. If you're prepared to reseason after, go for it. Otherwise, stick with hand-washing.

Do I need to concern myself with the quality difference between skillets?

For the most part, no. Whether it's Lodge or vintage Wagner, old rules don't change. It really depends on personal preference. Though, it can help when you're buying in person, since you can feel the pan's weight and grip. Don’t worry too much about what you’re buying. Instead, focus more on getting used to what you’re holding.

A final note

I love my cast-iron pans for grill-roasting peppers and barbecuing. They're also versatile and sturdy enough for baked goods. They're not as intimidating as they seem, and they can last lifetimes. If there's anything you take away today, let it be this. You can almost always recover these pans from any state that they're in.