How to Clean Cast Iron Grill Grates – If Rusty, Or Just After Grilling

There are many reasons to purchase cast iron grill grates.

They are incredibly durable and if looked after properly, will likely outlive your grill. They’re also able to retain an even heat during cooking and produce fantastic grill marks on your food.

On top of that, with continuous use and with routine seasoning they will eventually become non-stick; similar to a cast iron pan.

Close up of grill brush cleaning cast iron grill grates
© Mark Jenner / FoodFireFriends.com

However, just as cast iron pots and pans can rust in your home, cast iron grill grates can also become rusty and unusable if not properly cleaned and stored.

So in this article, we’re going to explore routine maintenance, how to clean cast iron grill grates and how you can keep your investment looking good and operating properly.

How to Clean Cast Iron Grill Grates

This is going to sound obvious, but cannot be overstated: The best way to keep your grill clean and rust-free is to give it a good cleaning immediately after every use.

Once you’ve finished cooking and removed your food, open all vents if using charcoal, or turn up your grill to high if using gas and then close the lid to allow the grill to get hot.

This way you’re able to burn off much of your stuck on food and barbecue sauce.

Once you’ve burned off your food, you can either close your vents to extinguish your charcoal (which can be reused,) or turn off your gas to allow the grill to cool to a point where it’s comfortable to put your hand in to clean.

While your grill is still warm, scrape the grates with a good grill brush.

A brush with a scraper is excellent here as you’re able to scrape any remaining food off your grates easily.

After cleaning your cast iron grates and making sure they’re dry, you now want to apply a very thin coating of vegetable oil to help prevent rust from forming.

Just a wipe with a cloth or piece of kitchen towel lightly dabbed in oil is sufficient. You’re looking to apply a thin film, not coat your grates heavily.

How to Remove Rust From Cast Iron Grates

Sometimes accidents or unintentional neglect can happen, and your grates will sadly become rusty.

This can occur if you accidentally leave the cover off your grill, or if you simply don’t use it for a prolonged period and moisture gets inside the grill.

If this happens, don’t panic – there are several ways you can remove rust and restore your cast iron grates to their former glory.

Steel Wool & Soapy Water

I think I should begin by saying this: Do not wash your cast iron with soap and water unless you want to strip your seasoning and then re-season it again.

In the below video, we see how Lodge Manufacturing, one of the oldest cookware companies in the United States and one of the largest manufacturers of cast iron cookware in the world, gives recommendations on how to clean grates that have become rusty.

 

So long as your spouse will allow it, bring your grill grates inside the house and wash them in the sink with hot soapy water and steel wool or a stiff brush. This will remove any seasoning you’ve built up, but will also remove any surface rust, bringing your grate back to bare metal.

Once cleaned you will need to give your grates a good rinse before drying them very thoroughly. You don’t want any moisture left behind because that will cause rust to come back again very quickly, even as quick as overnight.

The best way to dry them is a few minutes sitting in a very low oven, to completely make sure there’s no water left in any pores.

Vinegar Soak

If your sink is large enough to lay your grill grates flat you can simply soak them in vinegar to remove any rust.

Start by making a 50/50 mixture of water and distilled white vinegar, and let the grates soak for about an hour. Then gently scrub with a kitchen scrubber or wire pad to remove any remaining rust.

Once finished scrubbing, you’ll still want to wash with soapy water to rinse off any remaining vinegar, followed by drying thoroughly in a low oven.

Self-Cleaning Oven/High Heat on the Grill

If you have a lot of rust on your grill, you may have to take more drastic measures than simply cleaning with soap and steel wool or soaking in vinegar.

A sure-fire way that’s been used to clean cast iron for years is to simply run it through your ovens self-clean cycle. If you don’t have a self-cleaning oven you can get the same results by leaving your grates in an extremely hot grill (like 600°+) for over an hour.

Once your grates have cooled (either inside the oven or on the grill), you’ll still need to give them a quick cleaning with hot soapy water to remove any carbon that may have been left behind.

Oven Cleaner

If your grill has a lot of rust and/or baked on crud and you don’t think any of the above methods will work for you, then oven cleaner is the be-all end-all way of stripping all your cast iron down to bare metal.

Most oven cleaners contain lye, a strong alkaline solution used for washing and cleaning.

Before you start, assemble all required materials:

  • Oven cleaner
  • Garbage bags
  • A large enough box or container to store the grills for a couple of days while the oven cleaner works its magic
  • Some safety glasses and gloves.

In a well-ventilated area, spray an even coating on your grates, place them inside garbage bags, and seal the bags air tight. Now store them for a couple of days in a warm place where no children or pets could possibly get at them.

Once the crud has all broken down, rinse the cast iron and follow it up with a wash in soapy water.

Season Your Grates After Cleaning – This is Essential!

Regardless of how you cleaned your cast iron grates, you should always season them before you put them away.

Seasoning is simply the use of fat or oil that is baked into the pores of the cast iron at such a high heat that it polymerizes, forming a tough coating that prevents rust and forms a nonstick finish over time.

If your grill is hot and you’ve just cleaned your grates with a grill brush, one coat will be sufficient, but if you’ve just completed one of the more thorough cleaning methods described above, you’re going to want to apply a couple of coats.

You can use cooking oil to season your grates, but a product I’ve been using lately to season all my cast iron is Crisbee.

Made from bees wax, soybean & palm oil, it’s specifically designed for seasoning cast iron. I’ve been using Crisbee for about 6 months now, and my pans have never looked better!

Conclusion

How about you, what kind of grill grates do you own? Have you ever cooked with a cast iron grill grate in your backyard? Have you any tips or tricks for keeping them clean that we haven’t covered here?

Leave a comment below to tell us what kind of grates you own and how you clean them, we can all learn from each other!

Happy grilling!

Mark Jenner

Hi. I'm Mark Jenner, owner and creator of FoodFireFriends.com. I grill and smoke food outdoors at least three days a week on a wide range of equipment, have done so for years, and love nothing more than cooking good food, over live fire, enjoying it with friends. The aim of this site is to educate and help others to do the same.

4 thoughts on “How to Clean Cast Iron Grill Grates – If Rusty, Or Just After Grilling”

  1. Crisbee doesn’t actually recommend their product for barbecue cast iron grilling grids because the high heat will remove “seasoning”.

    • Hi Isabel,

      Thank you for your comment 🙂

      The same could be said for any cast iron seasoning method. I’ve yet to find any that survive the high heat of a good searing session. However, for me I still like to re-season when finished before putting the grates away.

      I used to just give my grates a wipe with oil when I was finished, then put them into storage. However, I have so many cast iron grates: Some for the KJ classic, for the big joe, for my weber kettles, a plancha for the weber kettles, one for my go anywhere…and a few more besides.

      This means that sometimes, a cast iron grate of mine may not be used for months while I use other equipment. I found that while in storage, if I only wipe them with oil then store, rust spots can and do appear almost every time. So nowadays, after I have finished grilling, I remove my grates and allow them to cool and close down the vents a bit to reduce the heat, then use the lower remaining heat in the grill to re-season the grates before putting them away. This is the only way I’ve found to prevent rust long term.

      So for me, while I agree with your statement that when searing the seasoning gets burned away, (and this has been true regardless of seasoning method I have used) it is still important for me to season the grates before putting them into storage, otherwise they will rust.

      It’s a never ending battle…but part of owning and using cast iron grates I’m afraid.

      Can I ask what you advise? I might be missing a trick and am always looking to learn 🙂

      Mark.

  2. I have 3 long cast iron grills on my natural gas stove that need cleaning. If I place them in hot coals to remove greasy build up, how do I treat them as soon as I get them off the coals ??

    • Hi Cora,

      Sorry, I don’t quite get the question…could you clarify a bit please?

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