Andrew Zimmern's Major No-No When It Comes To Cooking Tomatoes

Andrew Zimmern loves tomatoes. He shared on his website, "I buy buckets of them at the farmers market to supplement my harvest and turn half into sauce, the other half I halve, toss with olive oil and roast in a 225-degree oven for 6 or 7 hours."

But whether you roast these red fruits for a pizza or pasta dish or use them for a one-pot tomato soup, Zimmern says you don't want to cook them in anything made of soft metal, especially aluminum pots and pans. He thinks you should even avoid using aluminum utensils when preparing tomato recipes. But why is this an absolute no-no?

Again, Zimmern explains on his website, "The acidity in the tomato doesn't do well with them, they create a chemical reaction and can turn cooked tomatoes bitter, fades the color and the food will absorb some of the aluminum!" And if you use your aluminum pots to cook tomatoes in, chances are they aren't going to look very pretty after the fact. The TV host and entrepreneur further said, "The acid in the tomatoes can pit and discolor the aluminum cookware. But you shouldn't be cooking with those anyway."

He isn't wrong. Aluminum pots and pans that are uncoated do pose a risk of leaching, especially when you cook foods like tomatoes that are acidic, and no one wants their Italian tomato sauce to develop a metallic taste. However, before you get rid of a pot or pan that is aluminum you should know that if your aluminum cookware has been anodized, meaning it has been coated with a protective layer, you can use it to prepare your red sauces and soups. Just examine it to ensure it is free of scratches and the protective layer has not been compromised.

So can you use cast iron when making tomato-based foods? Sadly, the answer is it is best not to. Acidic foods that require a long simmer can ruin all that seasoning you worked so hard to achieve. In turn, it will make your food taste a little tinny. So save your cast iron for your giant gooey skillet chocolate chip cookie and stick to stainless steel cookware. Your cast iron will thank you. Additionally, tomatoes — as well as wine and vinegar — can be a buzz killer for the beauty of your copper pots. Copper is reactive with acids as well, but it depends on what these pots and pans are lined with. If your copper pots are lined with tin, then you can go forth and cook your tomatoes without fear. 

If you are feeling a little skittish and wondering what you should use instead of aluminum to cook your tomatoes, try cooking them in a stainless steel pot or a ceramic pan or skillet. In contrast to aluminum, both types of cookware are non-reactive and can be used with acidic foods like lemons and tomatoes and liquids like wine and vinegar without any worries. Zimmern himself is a fan of carbon steel and an even bigger fan of All-Clad.

But that's not the only tomato knowledge bomb Andrew Zimmern is dropping on his cooking fans. The celebrity chef noted that once you find the right pot or pan to cook them in, the acidic properties of tomatoes can cause other foods cooked with them to cook a little slower. He explained that if you are making beans in a tomato broth, you can expect the beans to take at least 20% longer to cook. This is because tomatoes have a pH that ranges between 4.3 and 4.9; as they release their juices, they also release those acids. The longer they cook, the more acidic they become. So next time you're due for a long simmer, remember to use the appropriate cookware for your beloved tomatoes.