How to Protect Your Cast-Iron Skillet While Grilling | Reviews by Wirecutter

By Maki Yazawa

Maki Yazawa is a writer focused on making cooking fun. She once cooked for Natalie Portman, and her friends won't let her forget it.

When a cast-iron skillet is properly taken care of, it can last a lifetime. But cast-iron cookware isn’t invincible.

Despite seeming like an indestructible kitchen workhorse, a cast-iron pan can be highly susceptible to fluctuating temperatures, such as when you put a cold skillet on a hot grill. So preventing thermal shock (a drastic temperature change that can wreak havoc on even the sturdiest cast-iron cookware) is crucial.

Since grilling season is just around the corner, we tapped several experts for their advice on how to avoid temperature-inflicted damage on a precious cast-iron skillet.

Thermal shock is when a material is damaged due to a sudden temperature change.

When cast iron heats up, the metal expands, and when it cools down, it contracts, according to cast-iron expert Chris Wing. Known as Cast Iron Chris on social media, Wing is also the host of a YouTube series called Basics of Cast Iron.

“If this process happens too rapidly, it creates uneven heating and cooling, and since cast iron isn’t as flexible or malleable as other metals, the uneven expansion and contraction can create internal stress on the material,” Wing explained. He said this reaction can cause the cast iron to warp, crack, or, in extreme cases, split in half.

If a cast-iron pan or skillet comes from a cold environment and is heated quickly — whether on an electric stove, an open fire, a grill, or in an oven — the risk of thermal shock increases. Senior staff writer Michael Sullivan, who co-wrote our cast-iron skillet guide, said you can also shock a hot cast-iron skillet by running it under cold water (or transferring it to another equally cold environment, like a refrigerator or freezer) without allowing it to cool first.

Enameled cast iron (cast-iron cookware coated with a layer of enameled glass) is also at risk of thermal shock. Wing pointed out that vintage or antique cast-iron pieces (which are very thin and light) are more susceptible to damage than modern pieces (which tend to be thicker and more durable).

Wing assured us that the risk of thermal shock happening to cast-iron cookware while you’re grilling is relatively low. But if cast-iron cookware is handled incorrectly, thermal shock can happen during other routine activities. For example, it can occur if you wash a cast-iron skillet without allowing it to cool first. Thermal shock can also happen if you place your pan in or on a piping-hot appliance — like an oven, a stovetop burner, or a grill — without gradually warming it up first.

In some cases, damage caused by thermal shock is highly noticeable. For example, a cold cast-iron pan might split in half when it’s exposed to a piping-hot heat source. But sometimes the damage isn’t as dramatic. “Some older pans may experience ‘microcracking,’ small surface cracks that aren’t as noticeable to the naked eye and make a pan more susceptible to breakage over time,” Michael said.

Drastic temperature changes can exacerbate these fissures, big or small, so it’s important to avoid thermal shock whenever possible.

The easiest and most effective way to prevent thermal shock is to gradually warm up (or cool down) cast-iron cookware.

Lodge, the manufacturer of our top-pick cast-iron skillet, recommends pre-heating cast-iron cookware for three to five minutes on medium-low heat before increasing the temperature to the desired setting.

When you’re grilling, Wing said you should place cast-iron cookware on the grill grates while they’re still cold. Then turn on the burners, close the lid, and gradually warm up the cast-iron pan until it’s evenly heated through.

If a cast-iron pan has been in the refrigerator or another equally cold environment, Wing recommended leaving it out at room temperature for at least 10 minutes before putting it on the grill, to avoid thermal shock. To ensure a cast-iron pan has sufficiently warmed up, Wing suggested using a probe thermometer with a built-in infrared sensor to check the temperature.

Cast iron is excellent at retaining heat. If a cast-iron pan overheats and starts smoking while you’re cooking, Wing said it’s best to remove the pan from the grill, using a heat-proof glove, and lower the burner intensity. Then let the pan and grill cool down before you continue to cook. After a few minutes, he suggested using the infrared thermometer to check that the grill and pan are back to the desired temperature, to avoid damaging the pan and overcooking your food.

This affordable pan is lighter than a traditional cast-iron skillet and a little shallower. The shape makes it versatile and ideal for searing, roasting, and sautéing.

Although high temperatures aren’t exactly considered thermal shock, Wing said exposing cast-iron cookware to extreme heat (anything over 1,000 ºF) can also damage and cause warping or cracking.

Even sustaining temperatures at around 650 ºF can cause a cast-iron pan’s seasoning to start breaking down, according to information on Lodge’s website. However, many gas grills, including Weber’s, will max out between 500 ºF to 550 ºF. So exposing cast-iron cookware to extreme heat on those grills shouldn’t be cause for concern.

Some infrared grills, like the Charbroil Pro Series 3 Burner Gas Grill & Griddle, can reach much higher temperatures than most conventional gas grills. According to Charbroil’s website, when you’re cooking on a grill equipped with its Amplifire infrared technology, you should reduce the heat settings by about 30%, and cut the cooking time by about half, to prevent overcooking food.

While testing the Charbroil Pro for our gas grill guide, staff writer Kathleen Squires found that it caused dangerous flare-ups and reached extreme temperatures, which can pose a risk to cast-iron cookware. So it should be used with caution. (These are just a few reasons why we don’t recommend this grill in our guide.)

Cast iron can retain heat for longer than aluminum and stainless steel. So you’ll want to give your cast-iron skillet ample time to cool down before cleaning it. “Adding cold water to a hot pan is a terrible idea,” Wing reiterated. However, if there’s a lot of stuck-on food, to help dislodge it, Wing said he sometimes deglazes a pan, using liquid only, if the pan is under 400 ºF.

When you’re letting a cast-iron pan cool, Wing said it’s fine to leave it on the grill with the burners off and the lid open. But he said you’ll want to avoid leaving the pan on a grill overnight or in a humid or moist environment, since rust can build up quickly.

For a step-by-step tutorial on how to clean (and season) cast-iron cookware, check out our guide. Then you’ll be ready to use your cast-iron cookware all summer long — and beyond.

This article was edited by Megan Beauchamp and Maxine Builder.

We’ve tested numerous methods and products to find what’s best to restore, clean, and season cast-iron cookware.

After testing 16 cast-iron skillets, we recommend the Lodge Chef Collection 12 Inch Cast Iron Skillet. It’s lightweight, sears well, and releases foods easily.

The Lodge 6 Quart Enameled Cast Iron Dutch Oven has been our top pick since 2015 for its ability to braise, sear, and bake as well as more expensive pots.

With proper care, Lodge cookware can truly be a buy-it-for-life thing.

Maki Yazawa

I’m a writer covering kitchen topics.