A question about a recipe: My Grandmother's Tomato Bisque: Cast iron and tomatoes!

I'd love to know why this recipe specifically calls for a cast iron pan. I've only (accidentally) cooked tomatoes or other acidic things in a cast iron pan a couple of times, and had horrible results. Is it a matter of time? I've always used a well-seasoned pan, but the finished dish was positively bitter and metallic. So what gives? And couldn't the same result be achieved with another sort of pan? This soup sounds lovely, and I trust that it works, but I'd like to understand it a little better.

sarah k.
My Grandmother's Tomato Bisque
Recipe question for: My Grandmother's Tomato Bisque


The W. September 14, 2011
Yes indeed, you are all correct - works better with all clad or non stick. It just has to be a good, heavy pan.
hardlikearmour April 14, 2011
15-minutes is not that long. If you're afraid, you could do a single tomato, and just taste the tomato after the cooking to be sure. I assume A&M made it per recipe specs and were pleased with the result.
sarah K. April 14, 2011
The recipe says to put the tomatoes face down for 10 minutes, then flip them and cook another 5. Doesn't that seem like enough time to develop an off taste? I mean, I always avoid cooking tomato based things in cast iron, while I use it for everything else specifically for the iron benefits (especially while I was pregnant and borderline anemic), but I'm telling you, the stuff I've done with tomatoes in cast iron was positively yucky. I also cooked up some livers once in that pan, and they had a vinegar sauce that was inedible. Is it a long simmer that causes the pronounced yuck? Is 15 minutes just not long enough for very much to leach? Is this going to change the way I make curry?
hardlikearmour April 14, 2011
When you cook acidic things in cast iron, iron will leach into your food (not necessarily a bad thing healthwise, especially for women or vegetarians.) I'm guessing since you are not working with tomato juice you don't get too much metallic taste in this. I'd guess you could use a non-stick pan with similar results if you are okay with using non-stick.
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