Because of their durability and resilience, cast iron cooking grates are a popular grill feature. However, cast iron does have one enemy, and that’s water. This means that when the grates are exposed to excess moisture, they’re prone to rust—an unappetizing prospect, to say the least. The question is: Is it safe to grill on a rusty cast iron grill?
What causes rust to form?
As we mentioned, rust—also known as iron oxide—turns up when the metal is exposed to water. That’s why you’re more likely to find it on grills that lack the proper care and maintenance.
The grills provided at public campgrounds are a good example. Because they’re constantly exposed to the elements, there’s nothing to prevent the rust from forming.
Is it safe to consume food that’s been in contact with rust?
First, the good news: Ingesting small amounts of iron oxide will not cause any health issues. That means that yes, it’s safe to grill food on a rusty surface if you don’t have any other options (see Tips For Cleaning Rusty Grill Grates, below.
That said, it’s not a good idea to cook on rusty grill grates on a regular basis. First of all, those small bits of reddish-brown metal aren’t likely to enhance your meal. Second—and more seriously—consuming large amounts of iron can be toxic. Symptoms of iron poisoning include severe nausea and vomiting, abdominal pain, and diarrhea.
While you would have to consume a great deal of rust for any of these symptoms to appear, it’s still in your best interests to keep cast iron grates as clean as possible. If you continue to cook on a rusty grill over long periods of time, all that excess iron can build up in your bloodstream. This is particularly worrisome for young children, since their lower body weight puts them at greater risk for iron poisoning.
Can eating food cooked on a rusty grill cause tetanus?
No. Contrary to a popular misconception, tetanus isn’t actually caused by rust itself, but by a bacteria known as clostridium tetani. This bacteria tends to hang around the same places that rust does, hence the confusion.
Since the grill will be hot enough to destroy any bacterium, you don’t have to worry about tetanus when cooking on a rusty grill. However, it’s best to keep your tetanus booster up to date, especially if you spend a lot of time outdoors.
Tips For Rust Prevention
Now that we’ve ascertained that the occasional meal cooked on a rusty grilling grate isn’t harmful, let’s see what we can do to prevent rust buildup in the first place.
All too often, rust will form because the grates have been insufficiently or improperly cleaned. Because cast iron is easier to clean when it’s well-seasoned, seasoning should be your first step.
To do this, clean and thoroughly dry the grates, then apply a thin coating of a neutral oil, such as canola. Heat the grates in a low oven to allow the fat to seep into the metal, thereby creating a protective layer. (If you’re using a gas grill, you can use the burners of the grill itself instead of the oven.) For best results, this procedure should be repeated after each use. If you’re still unsure about the best method for seasoning, take a look at this video tutorial.
You can also help to prevent rust by using a wire brush to remove all cooking debris when you’ve finished grilling. This is especially important in the beginning, when you’re still in the early stages of the seasoning process.
Never use soap when cleaning cast iron grates. It’s not necessary, and it may damage the seasoning that you’ve worked so hard to achieve. We would also not recommend putting them in the dishwasher, as this will expose them to water for an excessive amount of time. Just give them a good scrubbing under hot running water, then dry thoroughly before putting them back on the grill. This works best if the grates are still warm to the touch when you’re ready to clean them.
Finally, invest in a sturdy grill cover that fits well and doesn’t leak. if you put your grill in storage for the winter, consider storing the grates in a separate area—inside the house, if possible. If this isn’t an option, check them regularly to ensure that no buildup is forming.
Tip: As an easy alternative, consider purchasing cast iron grill grates with a porcelain coating. In addition to being easier to clean, you won’t have to worry about rust buildup. Just take care not to use any metal utensils when cooking, as these can chip the enamel.
Tips For Cleaning Rusty Grill Grates
You have several options when it comes to rust removal. Fortunately, most of them can be achieved using simple household ingredients. If you have access to any of the materials listed below, we would recommend using one of these techniques before putting food on a rusty grill.
Tip: If all else fails, you can place a couple of pieces of aluminum foil on the grate and cook the food on those instead. This technique works better if you fold the edges of the foil around the bars of the grate to anchor it in place. You might also want to poke a few holes in the foil to allow grease to escape, as the buildup could pose a fire hazard.
Every grill owner should possess a good wire brush. Just apply the brush to the surface and scrub back and forth until nothing is left behind except bare metal.
For cast iron, use one with relatively soft bristles that are sufficient for removing rust and food particles, but not so stiff that they’ll damage the metal itself. Alternatively, you can use steel wool or a balled-up wad of aluminum foil grasped in a pair of sturdy tongs.
Because vinegar is both inexpensive and safe to consume, it comes in handy for cleaning any type of cooking surface.
For this method, apply a generous amount of white vinegar to the rusty areas. Let it set for about 10 minutes, then use your brush or a wad of aluminum foil to scrape off the residue. Rinse the grates with water and repeat the process if necessary.
Mix baking soda with small amounts of water until a thick paste forms. Rub the mixture on the grates and let sit for about 1 hour. Scrape with a wire brush and rinse with warm water.
If the baking soda paste didn’t work, try repeating the same process with a paste made from kosher salt and a little bit of water. The solution will be more abrasive, which should do the trick. Repeat as many times as needed until the grates are rust-free.
Blend plenty of lemon juice with a powdered dish detergent and apply it to the grill grates. This procedure will take longer than any of the aforementioned techniques. For best results, you’ll need to let the mixture sit overnight before rinsing the grates with warm water.
Commercial Rust Remover
If all else fails, you can use a commercially prepared product to tackle your rust problem. Just make sure to choose the kind that’s designed for use on cooking surfaces. The chemicals in some rust removers can leave behind chemicals that are toxic when consumed.
The Bottom Line
So, when all is said and done, is it safe to grill on a rusty cast iron grill? The short answer is yes, but it’s not a good idea to do so on a regular basis.
Because rust removal is a fairly simple procedure, you’re better off if you clean the grill grates before you start to cook. We hope this guide has given you all the information you need to keep your cast iron cooking grates in prime working order.