Acidic foods, like tomatoes, will have a chemical reaction based on the type of cookware you use. If you love to cook, then you likely already have an array of cookware in your cabinets, from cast-iron skillets to stainless-steel saucepans. These types of pans serve different purposes, though, based on how the food you cook will react to them. This is because they fall in two separate categories: reactive and non-reactive. Before you reach for a pan to cook your next meal, it’s important to understand the difference between reactive and nonreactive pans, which will ensure you always reach for the correct pan for the task at hand.
I’ve been cooking for years, and I can’t tell you how many times I’ve grabbed the wrong pan and ended up with a metallic-tasting sauce—yuck! Knowing which pans react with acidic foods like tomatoes or citrus can save you from ruining a dish. Let’s break it down so you can choose the right cookware every time. For example, a quick tip I learned is to always keep a couple of nonreactive pans on hand for those tangy recipes—it’s a game-changer. Plus, understanding the science behind why certain metals react can help you make smarter choices in the kitchen. Acidic foods have a pH below 7, which can cause certain metals to leach ions into your food, altering flavors and sometimes even the safety of the dish.
Reactive Pans
“A reactive pan is one where highly acidic foods, such as tomatoes, citrus, and wine, react with the metal while cooking or storing these items,” chef Jim Warner, the program director of food and nutrition in the nutrition services department at The Ohio State University’s Wexner Medical Center, says. “This can draw a metallic taste when cooking or storing foods in a reactive pan or bowl.” Commonly used reactive cookware includes cast iron, however, it is also the least reactive type explains Warner, as most cast-iron pans are seasoned with cooking oil which reduces the chance of it reacting with highly acidic foods. Aluminum cookware is another popular option that is reactive. “An example of aluminum reacting with acidic foods is when you cover a tomato-based food with aluminum foil such as lasagna,” Warner explains. “When you remove the aluminum foil, you may see small holes in the aluminum with dark spots on the food where the aluminum has made contact with the food; the underside of the foil will also be discolored.” If you have aluminum pans that are coated with Teflon or other nonstick cooking surfaces, then they would actually be considered nonreactive (which we’ll get to next). “Unlined copper cookware can react with acidic foods but is safe to use when lined with another metal such as tin,” Warner explains. “Using unlined copper pans will leave your foods with a bitter metallic taste.” This is the result of the metal leaching into your meals from the chemical reaction of the food, metal, and heat when cooking.
I once made the mistake of simmering a tomato sauce in an unlined copper pan, and let me tell you, the metallic aftertaste was not what I was going for! Beyond the taste issue, reactive pans like unlined copper or aluminum can sometimes release small amounts of metal into your food, which might not be ideal for health if you’re cooking acidic dishes frequently. For instance, studies suggest that excessive aluminum exposure over time could be a concern, though typical kitchen use is generally safe. To avoid this, I always check if my cast-iron skillet is well-seasoned before tossing in something like a citrusy marinade—it’s a simple trick that saves the flavor. If you’re on a budget, cast iron is a great choice since it’s affordable (often under $50 for a good skillet) and, when seasoned properly, can handle most dishes with minimal reactivity.
Non-Reactive Pans
In contrast, non-reactive pans will prevent chemical reactions when cooking with foods high in acidity. Two of the most popular types? Stainless steel and tin. “Manufacturers of stainless cookware may line the bottom of the cooking vessel with copper or aluminum due to stainless steel being relatively a poor heat conductor, with aluminum or copper enhancing the conductivity of the pan [in turn, making this reactive cookware],” Warner says. “Tin-lined pans are also a good choice, as tin does not react with food. Again, manufacturers may line cooking vessels with tin.” There are other options on the market, too, like nonstick and Teflon. Keep in mind that some other types of cookware are great, but require particular care when you are cooking with them. “Cookware made ceramic, glass, or coated with enamel are also a good choice but you must avoid chipping or scratching the cooking surface or some of the material may end up in your food,” he adds. Using a wooden, rounded spoon on your pans will help, as it won’t scratch the surface and the shape will allow you to get in the corners of your pans. Softer wood in particular is what Warner suggests using when caramelizing foods and reducing sauces.
I’ve got a stainless-steel saucepan that’s my go-to for making lemon curd or tomato-based pasta sauces—it’s a lifesaver because it doesn’t mess with the flavors. One thing I love about non-reactive pans like ceramic or enamel-coated ones is how easy they are to clean, but you’ve got to be gentle. I learned the hard way that a scratched nonstick pan isn’t just annoying—it can release tiny bits of coating into your food, which is a no-go. A practical tip? Invest in a set of silicone or wooden utensils; they’re usually under $20 and will extend the life of your pans. Also, if you’re shopping for non-reactive cookware, stainless steel is a solid pick because it’s durable and often more affordable than high-end copper or tin-lined options—a decent stainless-steel pan can cost as little as $30 and last for years with proper care.
Caring for Your Cookware
In order to keep up the quality of your cookware, Warner says avoid using an abrasive brush or cleaner on Teflon-coated pans. Simply use dish soap or baking soda with water for a cleaning solution, as strong chemicals that could wear at the quality. If your Teflon pan’s surface starts to chip or peel, you’ll know it’s time to throw it out. For aluminum or stainless-steel pans, Warner says his go-to is Bar Keepers Friend which he uses with a soft cloth and water. He adds that you should let glass or stainless-steel cookware cool down completely before washing. “Temperature shock may damage the pans over time and the glass may shatter.”
I can’t stress enough how important it is to treat your pans right—think of them as an investment! I used to scrub my nonstick pans with a rough sponge, and they wore out so fast. Now, I stick to a soft cloth and a bit of baking soda, and my pans look almost new. For my stainless-steel skillets, Bar Keepers Friend is like magic—it gets rid of stubborn stains without scratching, and a small can costs less than $5. One thing I’ve noticed is that letting glass cookware cool naturally before washing saves you from those heart-stopping moments when you hear a crack. Also, if you’re like me and hate scrubbing, soaking your pans for 10-15 minutes before cleaning makes a huge difference—it’s a lazy cook’s best friend!
