I've had the same happen with acidic sauces. Particularly lasagna. I refused to toss the whole thing IâÂÂd worked so hard on, so removed the top layer of noodles, added more sauce and cheese and put it in the oven.

Yes. I've had it happen and the tomato sauce is dark where it ate the foil. There were some bubbles too. Fortunately it hadn't gone very far and it was a thick sauce that hadn't mixed so I was able to spoon off the bits of sauce that had reacted with the foil.

If I need to cover something that has an acidic (usually tomato) sauce, I now put a piece of parchment paper or waxed paper on top and then put the foil over that so there is no contact between the foil and the food.

I've only noticed it recently and I've wondered if they changed something about the foil. Like maybe it used to have a coating that prevented this. I haven't changed brands of foil.

I was going to just through the whole thing out. Maybe I can spoon off the spots. I noticed the sauce was darker in those spots too. I was using reynolds foil. It maybe that foil has changed over the years.

Not having a good cooking/food day. First I find my lunch of stuffed shells has foil in it. I can't get the jalapeno taste off my hands. I over filled my crock pot and it is taking a long time to get up to temp. My bread dough seems to be rising too fast. What a day!

I don't like to store or cook in foil, but sometimes it's the best fit for a pan, but I always put wax paper or parchment (not crazy about plastic wrap on my food either) between the food and foil, so maybe that would work next time.

I think the quality of the foil has changed and also beware that some foil, (some of the non stick) will not do good in higher temps. If it is aReynolds product, I would contact them and complain. It could be the foil made in other countries has who know what in it. Let them know what happened and also check your sauses, brands and where they are made.

Acid will react with aluminum, and eat through foil. There's nothing to complain about. The Reynold Release foil, with one non-stick side, will be okay, if only the "release" side touches the acidic sauce.

Foil has always done that in my experience.

It's not a new phenomenon to me either, though it's rare. In the FAQ section on Reynolds' site discusses this, and says the reaction can be unpredictable. They also say it's harmless, so no need to throw the food out:

" A similar reaction may occur when salt, vinegar, highly acidic foods or highly spiced foods come in contact with aluminum foil. The result of these reactions is a harmless aluminum salt. Some aluminum salts are used in medicines to treat stomach disorders. The food can be safely eaten; however, the aluminum salt particles can be removed from the food to improve the appearance of the food."

Here is a link that might be useful: Reynolds

I have had this happen, too. Acids are especially corrosive to aluminum so I always use glass or Corningware with any tomato based foods. And stainless steel cooking pots vs aluminum, i.e. 'non reactive' cookware. Since you've never had this happen before, perhaps the tomatoes you used were more acidic that others you've used in the past?

No point in complaining to Reynolds; it's basic chemistry that every cook needs to be aware of.

The difference for me is this was my first homemade sauce. For all my life I have always used a sauce like Prego. These were frozen tomatoes from our garden. Usually we just use those tomatoes for chili but I wanted to try to make sauce.

I don't understand the "aluminum salts" comment. It looked like the foil stuck to the food in little spots. Well, DH was looking for something to take to lunch today so I spooned off the spots. Then put the rest in a tupperware container.

So perhaps is was the homemade sauce with garden tomatoes that had a higher acid content then my usual Prego.

I don't understand the "aluminum salts" comment. It looked like the foil stuck to the food in little spots.

Acids are made of hydrogen atoms bonded to other atoms or groups of atoms. When they are in contact with aluminum, the aluminum attracts the "other part" more strongly than the hydrogen does, and that makes a new compound. The product of any reactions like this is called a salt (nothing to do with table salt).

Thanks Christine for the science lesson. You said it so plainly. Thank you for not sharing everything you ever read about the subject. ;)

Beware! I've always read that aged cheese can react with the foil. First putting down a layer of parchment paper or waxed paper on top of the cheese topping your casserole will prevent a reaction of the cheese eating through the foil. Same goes for wrapping pizza to freeze.

Teresa