How to Clean Cast Iron Grill Grates

This guide covers everything you need to know before you clean your cast iron grill grates.

Cast iron is one of the best grilling materials around, and for good reason. It’s durable, inexpensive, nonstick, and known for adding incredible flavor to food. If you own cast iron grillware, learning proper cleaning and maintenance is essential to keep your cast iron in great shape. This guide will show you how to clean cast iron grill grates.

To get the most out of your cast iron grill grates, it’s essential to clean them each time after using them. While it may seem like extra work after a long, hot barbecue, failing to properly clean the grates promptly can lead to residue buildup and rust.

The first step to cleaning your cast iron grill grate is seasoning it before you first use it. While this may sound odd, considering the grate hasn’t gotten dirty yet, seasoning it with cooking oil will improve the performance of the grill grate and insulate the iron against rusting.

Don’t use soap to clean your cast iron grates! It can strip off all the seasoning and leave the iron vulnerable to dangerous and costly rust. Instead, harness the power of your grill to clean your grates for you.

The first step is heating up the grates immediately after you finish cooking. If you own a gas grill, turn it up to high and close the lid. Charcoal grill owners should open up all the vents and close the lid to seal in as much heat as possible.

Heating up the grates right after you finish cooking will burn off most of the residue, saving you both time and energy. It’s important not to waste time -- the longer you wait after cooking to heat the grates, the more “set-in” the residue will become and the harder it will be for your grill to burn it off the grates. 

After you’ve heated the grates, let the grill cool for a little while. You’ll need to wait until you can comfortably put your hand inside the grill without burning yourself, but you want to keep it warm to make your job easier.

Use a grill brush and a scraper to clean each grate. Take your time and make sure to scrape off everything you can -- it will pay off in the long run! 

If some residue refuses to come off even when you scrub it, you can mix some kosher salt or baking soda with water to form a paste. Apply a bit of the mixture to any problem areas and scrub it with a brush or nylon sponge to remove the buildup. 

After cleaning your grate, you’ll need to season it properly to increase the lifespan and protect against rust.

Cleaning and seasoning your cast iron will help it form a protective layer of oil, toughening the grate and protecting it against rust. As a bonus, this also creates a nonstick surface for cooking.

You should season your grill grate before you use it for the first time. To break it in for the first cleaning, give it a good rinse with warm water and dry it with a towel. Remember not to use soap! After you’ve used it and seasoned it before, you can skip this step to help avoid any unwanted rust.

After rinsing your grate, use a paper towel or brush and cover the grates in your preferred cooking oil. The exact type of oil isn’t important -- some people prefer standard vegetable oil, while others opt for peanut, olive or grapeseed oil, among others. 

If you’re seasoning your grate for the first time, add several layers of oil to build up a coating of seasoning and seal out water and harmful moisture. If you’re just doing a standard cleaning, feel free to only apply one layer -- just make sure you cover every pore so no moisture can get into the grates.

After seasoning your grate, the last step to properly clean it is to heat it once again. The easiest way to do this is to put your grates back inside your grill, close the lid, and heat them for around 45 minutes at 350-400 degrees Fahrenheit. If you’re looking for a shorter alternative, you can also wrap your grates in aluminum foil and heat them for around 10 minutes instead.

If you follow the proper maintenance directions above, you shouldn’t have any problems keeping your grill grates free from rust. However, even short periods of neglect or unforeseen accidents can let moisture into the grates and compromise the cast iron.

If you do find rust on your cast iron grill grates, there’s no need to worry. Except for the most extreme cases where rust has eaten through the cast iron itself, it’s still possible to clean rust off your grates and restore them to good working condition. There are several options to clean the rust off your grates, each with different pros and cons.

If the rust buildup on your grates isn’t too severe, you may be able to scrape it away with just steel wool or an abrasive cleaning brush.

To use a brush or steel wool pad, simply find any areas with rust buildup and scrub them until the rust begins to flake off. Make sure you inspect the grates carefully to remove all the rust before you begin using them again as normal. And beware, as this method definitely requires some elbow grease!

If the pad alone won’t clean your grates, you can also use some soapy water to help get the rust off. While this method will clean your grate, it will also remove all your built-up seasoning, so only use this method if other methods have failed. 

To clean the grates with soapy water, bring them out of the grill and wash them as you might any other dish with hot soapy water and a firm brush. You don’t need to soak the grates, but if there’s any excessive buildup soaking the grates could help scrub it off.

Once you’ve washed the grate with the soapy water and brush, you must rinse off your grates and dry them thoroughly. Finally, you can season them with some oil to begin rebuilding your seasoning coat.

Because any moisture can cause cast iron to rust, failing to properly dry your grates after washing them with water is a recipe for additional rust. In some cases, the rust can return just days after cleaning the grates.

If you’re worried about making sure your grates are completely dry, putting them in the oven at a low temperature for a couple of minutes can ensure no moisture remains after washing them.

If you can’t get the rust off your grates with just some steel wool, and you don’t want to completely strip away your seasoning, a vinegar soak is a tried-and-true option to clean your cast iron grates.

Simply remove the grates from your grill and soak them in a 50/50 mixture of white vinegar and water for roughly an hour. If you need a more serious cleansing agent, you can also use a combination of two parts white vinegar to one part baking soda and soak the grates for hours.

Once you’ve finished soaking your grates, the rust and other residue should brush off much more easily. Then, you’ll need to rinse your grates to remove any leftover vinegar and dry them (preferably at low temperatures in an oven). Finally, brush them with oil to aid your seasoning.

If you’ve tried every other method and the rust won’t come off your grates, oven cleaner may be your last hope.

Spray an even coating across your grates and seal them in garbage bags to lock out any air. Oven cleaner can be dangerous, so make sure you do this in a well-ventilated area. Store them in a warm and dry place for a few days to let the oven cleaner work.

After a few days, wash and scrub the grates with soap to remove any rust and oven cleaner and rinse thoroughly. You’ll have to start re-seasoning your grates from scratch, but this method is the strongest way to remove the most stubborn rust.