So I’ve always cooked tomatoes (or other sour foods) in Teflon pans. Now I’m thinking that perhaps the acidity was damaging the nonstick lining and making stuff leach into the food.
Were these pans meant only for non-acidic cooking?
Everything I’m reading in a quick google suggests that Teflon is fine with tomatoes and stuff. What tends to scratch things up is getting it too hot or using metal utensils that scratch it up. And a lot of things say to avoid using any cooking spray with lecithin in them (i.e., most cooking sprays), because the spray itself can stick to the pan, causing the lecithin to react more with the coating.
But that’s only Teflon: there are other non-stick coatings now that can handle cooking spray. Or, at least, the instructions say to use it—like in my waffle iron. But others say to avoid it, like in my pressure cooker/air fryer combo.
Tomatoes are tough.
But I think if your Teflon/nonstick coating is in good order I don’t think they would suffer from just cooking tomatoes/acidic foods.
Don’t cook them in a cast iron skillet, tho’, unless you want to re-season.
Never mind tomatoes. Invest in a decent set of stainless steel pans - they will take just about anything you can throw at them.
Teflon pans date from the 1970s and are rather fragile both physically and chemically. Non-stick pans using other coatings or finishes pretty well replaced Teflon by the late 1980s and are vastly more durable. What surface finish specifically are you actually talking about?
Assuming you’re not talking real Ye Olde Fashione Teflon, IMO you just about can’t hurt the finish chemically. Tomatos shomatoes; it’s all fine.
@bob_2: you do you, but I find straight stainless pans almost useless. Everything sticks, nothing ever comes clean, they’re not quite single use, but close.
I’ve heard that tomatoes and tomato products shouldn’t be cooked in cast iron pans because the acidity can leach excess iron into the food.
Teflon is highly resistant to acids. If your pans have problems, it wasn’t because of acids from food.
I have a stainless steel pan that gets a fair bit of use. They are great for some things like cooking a steak which leaves fond in the pan which can be used to make a delicious pan sauce. Non-stick pans don’t do that well.
I’d recommend Bar Keepers Friend. That stuff seems to clean anything (although not suitable for everything since it is abrasive…never use it on stainless steel appliances for example since it can scratch the finish…seen that happen and ruins the finish).
Also, if there is stubborn stuff stuck to the pan just soak it in water and a little dish soap for a few hours. That usually does the trick. If not, boil water in the pan. If that doesn’t work then not sure what you welded to your pan. 
Stainless steel is just way too much trouble. It’s fulltime work keeping up with my cast iron.
A non-stick set is a must in a kitchen like mine. My daughter’s cook frequently (well, mostly).
I’ve put the stainless in a box and stored it.
There’s a trick to stainless, and it’s to get it hot enough before throwing anything on it. It’s hot enough if you can flick some water on it and it turns into little beads of liquid that slide around and take a few seconds to disappear. If it vaporizes on contact, it’s not hot enough yet. It’s called the Leidenfrost effect. Basically, a layer of water vapor is created below the liquid and it kind of hovers over it without touching the pan itself.
That said, I rarely use the only stainless steel pan I have. I’m pretty much 50-50 cast iron and non-stick, minus about 5% for the stainless. My cast iron I cook anything in and don’t really baby except for when I’m dont cooking and cleaning it, heating up the pan and putting down a thin layer of oil that I wipe up, so it leaves a glistening surface. I even wash with soap and water fairly regularly. Once you got a good seasoning down, it’s darn near bulletproof.
With non-stick, the main thing I try to avoid is using any metal utensils on it to avoid scratching. Only wooden spoons and silicone utensils. This prolongs their life a good bit. I’ll go a few years before replacing non-stick cookware, but it needs (at least for me) to be replaced at some point. Stainless and cast iron should last indefinitely unless you really, I dunno, gouge it or something.
I use all three - copper-bottom stainless frying pans for chunks of meat, nonstick for omelets and other delicate things, and cast iron for everything else; stainless stockpots and saucepans and a cast-iron dutch oven. Ever since I learned to slosh some water into the pans and scrape up the fond while they’re still hot, I haven’t had any trouble getting the stainless pans clean - and you can scrub them with a Scotch-brite without worrying about the finish.
+1. Same for cast iron for me. Clean while hot if you have lots of crusties in there.
That’s strange. Maybe the quality varies - IDK. All I know is that I am still using, every day, the set of pans I bought 35 years ago when we furnished our house. The food I cook doesn’t tend to stick much, but I have boiled them all dry from time to time and a whizz through the washing machine and a quick scour for stubborn bits brings them up all shiny again.
I do use a non-stick frying pan that is about five years old and due for replacement as it’s not all that non-stick anymore.
This. PTFE is regularly used in industrial and chemical applications involving contact with acids. Tomatoes and other acidic foods won’t wreck it, but high heat will. You can brown meat in a Teflon pan, but you need to be careful about how much heat you use; it’s best to keep your stove’s power at medium or medium-low and take your time.
Tomato’s have a pH in the neighborhood of 4 - 4.5. My wife and I regularly make a barbeque sauce that starts with ketchup (pH = 3.9) and malt vinegar (pH = 2 - 3). The Teflon pan we use still looks fine.