How To Clean Cast Iron Grill Grates – Seasoning Is Rust Prevention

A steak on top of a cast iron grate over a hot fire
© davit85 -

Wonder how to clean cast iron grill grates? You’ve come to the right place. 

In this article, I will show you how to do so plus how to remove rust from them as well. I also touch on some of the benefits of using cast iron grates and why it’s important to season them regularly.

Let’s begin.

Why Do We Grill With Cast Iron Grates?

Cast iron grill grates have three benefits. 

Firstly, cast iron is very tough and sturdy. The material itself can take all sorts of abuse. 

It also conducts heat extremely well. And once it’s hot, it retains that heat for a long time. That’s why cast iron grill grates are excellent for searing and creating grill marks on your food. 

In addition to that, the more you use them, with correct maintenance and care, the better they get. To the point where their surface becomes non-stick, which is a bonus if you grill a lot.

However, the one downside of cast iron is its vulnerability to rusting. It’s due to not being cared for properly and constant exposure to water/moisture.

So the most important thing to prevent your cast iron grates from developing rust is to season them before cooking and after cleaning. Let’s learn how to clean them first.

How To Clean Cast Iron Grill Grates

Similar to stainless steel, I’d recommend cleaning your cast iron grates right after cooking. If you leave it until the grill cools down, that’ll take some elbow grease to clean them later.

With that said, you should still enjoy your meal before doing anything. Remove your food and close the lid. On a charcoal grill, open both top and bottom vents whereas turning all burners to medium or high heat on a gas grill. 

Doing so will heat up the grill again, which in turn slowly burns any food/sauce residue stuck on your grates. Leave it like that for about 20 mins then close all the vents or burners. Once you’re done eating, the grill will be warm enough for you to start cleaning.

With your trusty grill brush, start scraping off any remaining leftover on your cast iron grates. If you encounter some stubborn particles, mix a bit of vinegar or kosher salt with water, then apply the paste to the grates using paper towel. That will make those come off easier and sanitize the grates at the same time.

Tip: If you can’t find your grill brush, you can wad up a sheet of aluminium foil into a ball. Grab it with a tongs and that’s your makeshift brush.

The last, and most crucial, step is to season the cast iron grates. After cleaning them, wait for about 5 to 10 minutes until the grates dry out. Then dip some paper towel into any type of cooking oil and proceed to wipe it on your grates. 

A quick warning is that this will get a bit smokey from some of the oil dripping down to the fire.

You can also use a natural bristle brush if you want. Refrain from using nylon bristles since they will melt.

The key here is to apply just a thin layer of oil. So if you happen to put too much, use a clean cloth to clean off any excess. 

By now, the grill is starting to cool down. Close the lid, let everything as it is, and you’re good to go. 

Seasoning Is Rust Prevention

Cast iron is a porous material with a lot of pores. The purpose of seasoning it is to coat those pores with many layers of oil. Doing so repels water, prevents rust from forming as well as produces a non-stick surface over time. 

Keep in mind that you have to do this whenever you finish cooking as well as before that. The reason is because the heat (during cooking and before when you warm up your grill) will burn off some of the oil layers. Therefore, to maintain its integrity, you have to reapply another thin coat of oil every time.

It’s also best to put a cover on to keep water out of your grill, especially if you live in snowy or rainy areas. Also don’t forget to clean out the ash when the grill cools down the next day. Ash can hold in moisture which is a no-no for your cast iron grates.

Furthermore, you should inspect the grates often. Quickly remove any small spots of rust and season them right away.

Nevertheless, rust sometimes can get out of hand. The next section will show you how to remove it if your cast iron grates are completely rusty.

How Do You Remove Rust From Cast Iron Grill Grates?

Depending on how bad the rust is, here is the step-by-step process on how to remove it.

Step 1 – Get a container that is large enough for your cast iron grates. Fill it with a bottle of white vinegar and 1 cup of baking soda. Make sure that the grates are fully submerged. Leave it there overnight. If the rust is really bad, leave it for a few days.

You can also use other chemical solutions, such as Easy Off, to clean the rust. But remember to rinse off the residue after. 

Step 2 – Remove the grates from the container. By now, it will look much better than before. Get some steel wool or a brush and start scrubbing off any remaining rust. 

Even better if you have a drill with various wire brushes. That shouldn’t take too long with a power tool. You can also use it to initially clean the rust before soaking it in the vinegar and baking soda liquid.

All the scrubbing will get your grates back to just bare metal. 

Step 3 – Proceed to rinse the grates to get rid of all the rusty dust. After that, turn your oven to low heat and slowly dry out the grates. 

You can also pat dry it with a towel. Just make sure that there is no water left. Rust can come back really quick if you’re not careful.

Step 4 – The last step is to re-season the grates. Now, you can do that inside your oven. However, I find that it will get smoky and smelly inside the house. Therefore, a better solution is to use your grill.

Get your grill, either charcoal or gas, to about 350F to 400F and maintain that temperature range. A bit higher is fine too. 

Then apply several coats of oil on the grates. Close the lid and bake them. Check back every 20 to 30 minutes. Repeat this process until the grates are jet black, shiny, and smooth. This whole thing should take you a few hours to complete. 

Once the grates are good to go, don’t forget to season them before and after the next time you cook. That should keep them going forever. 

Here is a quick video showing the process above.

YouTube video


And there you have it – how to clean cast iron grill grates and how to remove rust from them.

They are an excellent accessory to have in your grilling arsenal. Cast iron grates are tough and durable. They also conduct and retain heat extremely well, which is great for high heat searing. 

However, they’re susceptible to rusting. The best way to prevent it is to season them regularly. Doing so will keep them in great shape and they eventually develop a non-stick surface.

So, do you have other ideas on how to clean or remove rust from cast iron grates? Drop a few lines down below and let everybody know.

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Thinh Phan

Thinh Phan

Thinh Phan is a barbecue enthusiast who fires up his grill regularly, at least 3 times a week. Combining the experience and his passion for outdoor cooking, he put together where he shares recipe ideas along with his knowledge of grilling and barbecuing techniques.

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