I’ve cooked anything and everything tomato in my stainless steel cookware: tomato soup, relishes, and even tomato jam in the summertime when the garden is overflowing. Have all these tomato dishes hurt my pots and pans? Not at all!
In this article, we’ll look at why acidic foods damage some types of cookware and not others and how to cook tomatoes in stainless steel cookware safely.
Can You Cook Tomatoes in Stainless Steel?
Yes, it is safe to cook tomato sauce and tomatoes in grade 304 stainless steel cookware – the most common grade for pots and pans. Stainless steel is a non-reactive metal and can safely handle both tomatoes and highly acidic foods like lemon juice and vinegar. Acidic foods may cause discoloration on your pots and pans, but it can be easily removed.
Cooking Acidic Foods in Metal Pots and Pans
Tomatoes are mildly acidic compared to vinegar and lemon juice. (Tomatoes have a pH of 4.2 to 4.6, while lemon juice has a pH of 2.0 to 2.6.) But both are acidic enough to cause chemical reactions with certain kinds of metal cookware. Aluminum and natural iron are notoriously reactive metal cookware choices. Cooking tomatoes in uncoated aluminum or iron causes an electrochemical reaction that deposits metal ions from the cookware into your food. This can result in flavor changes in your food and damage to your pots.
The longer you cook acidic foods, the greater the reaction will be. So, to cook tomatoes, especially for longer periods of time, like when you are simmering a sauce, you need to use non-reactive cookware – like stainless steel.
High-grade stainless steel is one of the best materials for cooking tomatoes because the nickel and chromium added to the iron alloy make it corrosion-resistant and much less reactive. Grade 304 stainless steel (also known as 18/10 or 18/8) has a high enough nickel and chromium content to handle acidic foods for normal cooking periods.
There is an often-cited study that showed cooking tomatoes in stainless steel for six hours could cause some nickel and chromium to leach into the food, especially with brand-new pots and pans. It’s something to keep in mind – but that is not a normal amount of time for cooking tomatoes.
Since the amounts of nickel and chromium leached in the study were lower than the FDA tolerances, cooking tomatoes in stainless steel for shorter periods of time in well-used stainless steel cookware should remain safe unless, perhaps, you have a nickel allergy and need to avoid nickel entirely. (In that case, check out nickel-free stainless steel cookware!)
Also, the study stated, “depending on the grade of stainless steel,” which means different grades of stainless steel had different levels of reactivity. But even 18/8 stainless steel, which may be used in budget stainless steel cookware sets, is safer to use for acidic foods than many other types of cookware!
Which cookware material is the worst choice for tomato sauce?
The worst type of cookware for tomato sauce is uncoated aluminum. The reaction of the metal with acidic foods like tomatoes will eat away at your pan and leave your food tasting bitter and metallic. Aluminum also heats so quickly that it increases your chances of burning the tomatoes.
Iron cookware (including cast iron and carbon steel) with poor, patchy, or no seasoning at all will also react to tomatoes. Thoroughly seasoned cast iron or carbon steel can handle a quick run-in with acidic foods, but letting tomatoes linger in the pan will quickly strip the seasoning.
Nonstick and ceramic-coated pans are also ones to avoid for tomatoes because the acidity can eat away at the coating, reducing its effectiveness.
Will tomato sauce ruin stainless steel?
Nope! Because stainless steel cookware is non-reactive, meaning it’s chemically stable and doesn’t react to acidic foods, even highly acidic foods like lemon juice and vinegar shouldn’t damage your cookware – let alone a tomato-based dish.
Can you make tomato soup in a stainless steel pot?
Yes, actually, I’m a big fan of it. There’s nothing better than a big pot of creamy tomato soup. Stainless steel pots are great for not just standard tomato soup but all tomato-based soups. I’ve made and enjoyed classics like minestrone, tortilla soup, chili, and my all-time favorite, a spicy lentil soup, in my stainless steel pots with no damage, discoloration, or deterioration.
Recommended Stainless Steel Pot:
Buttermelt 6 Quart Tri-Ply Stainless Steel Stockpot
What foods should not be cooked on stainless steel?
Except for frozen foods straight from the freezer (they can shock and warp your cookware if added to a hot pan!), there are no foods that I can think of that should not be cooked in stainless steel.
If you Google ‘what not to cook in stainless steel’ you’ll get people saying that it can’t handle more delicate foods like eggs, fish, and pancakes. But I’ve cooked all of these to perfection; you just need to use the right techniques! I have found that cooking a fabulous fish filet only takes a few minutes, as stainless steel excels at delivering a delicious caramelized golden crust and crispy skin.
Recipe for Cooking Tomato Sauce with Minimal Metal Leaching
Making a delicious tomato sauce like a versatile marinara is easy in stainless steel. Here’s a quick step-by-step guide on how to make it perfectly:
- Preheat the pan over medium heat.
- Test it’s ready by adding a few drops of water.
- Add oil and heat for a few seconds
- Add garlic and cook for about 10 seconds before adding the rest of the ingredients: chopped tomatoes, onion (cut in half; you will remove this later), oregano, a pinch of red pepper flakes, and bring to a boil.
- Once boiling, reduce heat to a slow simmer (lowest setting), stirring occasionally until the tomatoes break down and the sauce thickens to the consistency of your liking, usually about half an hour.
- Remove the onion halves with a wooden spoon and discard.
- Using the wooden spoon, smash up any tomato pieces left or press them against the side of the pot to break them up. You can use an immersion blender for a smoother consistency, but be very careful NOT to scratch the bottom of the pot.
- Serve while warm over pasta with crusty bread, or cool and store in the freezer for up to two months (mine never lasts that long.)
Buon Appetito!
Tip for success: Smash the garlic against the side of the pan with a fork after about 20 minutes for a more flavorful sauce.
Bonus tip: For a quicker cooking time, you can use canned tomatoes instead of fresh.
Conclusion
Yes, you can cook tomatoes in stainless steel cookware any way you can think of. Tomato soups and pasta sauces, tomato conserves, even tomato jam (which is delicious, by the way) I’ve been making them all for decades perfectly in my stainless steel cookware.
We’d love to hear from you! If you have any questions about cooking tomatoes in stainless steel or about anything else, please leave a comment below. We’ll get back to you once that giant pot of tomato soup comes off the stove.
