For many people, the zing of tomato sauce, especially if made from garden-fresh, ripe tomatoes, can be too acidic. A very common solution is to add sugar to the sauce. It works, but it also makes the sauce sweet; and I for one despise sweet tomato sauces. (How anybody can stomach that sweet, gloopy Prego stuff, when homemade tomato sauce can be deliciously and easily accomplished in about half an hour—or longer if you want a full-bodied, rich flavor—is beyond me.)
Another way to reduce the acidity of tomato sauces is to use baking soda. It’ll neutralize the acid, making the sauce bubble madly as it does, without adding calories or unwanted sweetness. I can’t offer proportions, as it depends on the acidity of the tomatoes and one’s taste preferences for tomato sauce; but I can say it doesn’t take much. I used a generous pinch last night in a sauce of approximately 25 ounces of tomatoes and juice, and I think it was a little too much. Just as one should do with seasonings, start small, and add if necessary, because you can’t take it out. Stir well after each addition, and taste after the chemical reaction (indicated by the bubbling) has abated. This does flatten the taste some, so do taste it, and if necessary adjust seasonings to compensate.
Oh, and I wouldn’t do this if I were making the tomato sauce in a cast iron skillet—I’m not sure how the reaction will go with iron in the mix as well, but you might end up with a very metallic-tasting sauce.
Update 5/08: For the benefit of those reaching this page via a search: yes, tomatoes are acidic fruits in general. However, varieties of tomatoes do vary in their acidity. If you’re looking to grow tomatoes and you prefer ones with lower acidity, some research will point you to the best low-acid varieties for your area. I believe—but I could be wrong on this—that yellow tomatoes in general are less acidic than red ones.
Regarding canned tomatoes: the acidity is standardized in the canning process. I don’t know if different brands pack their tomatoes under differing acidity levels, but if they do I haven’t detected much of a difference among them.
Tomatoes too Acidic?
Canned tomatoes, on the other hand ...
When tomatoes are out of season, I rely on canned tomatoes for sauces (I generally don’t bother with homemade salsas, unless fresh tomatoes are available; sometimes I succumb to the temptation of storebought fresh tomatoes but the flavor is always lacking for this use). They work pretty well, which was a surprise to me. I buy plain diced tomatoes, without any added seasonings, for maximum flexibility, and use them for pasta sauces, pizza sauces, and in Indian dishes too. There’s no metallic taste to them that I’ve been able to discern ... and the snolfs like to snitch pieces of tomato from the can, which is an endorsement too.
I’ve never made chicken vindaloo; my foray into Indian cuisine has been limited to vegetarian fare so far. (Can you believe that, my first time at an Indian restaurant, I looked the entire menu over, wondering why there were no beef items to be found? Fortunately I figured it out before I opened my mouth and said something stupid!)
Why reduce acid?
I seem to be a constant denier here, but I don't understand why anyone would want to reduce the acid in tomato sauce, etc. That's a big part of their distinctive flavor and character.
When I grow tomatoes, I specifically grow the varieties with the highest acid content I can find. Unfortunately, most modern kinds have far less acid than older varieties, and I've even had to ADD citric acid to home canned tomato products to insure proper preservation. Much the same can be said for many newer fruit varieties as well.
As for cast iron, if you wish to use baking soda to tomato products, I'd suggest you add it before you put anything into the pan, just to be sure. A reduced acid product will actually leach less iron into the food, but I don't know about the bubbles.
I don't use cast iron for acid foods anymore because I don't need additional iron in my diet. Post menopausal women and men can get too much iron, and this is one way to prevent overload. I now use a stainless steel pan for everything but browning meat. Nothing beats cast iron for that job. :)
Me too
I enjoy the zing of fresh tomatoes too, but some people apparently have problems with high-acidity foods. Baking soda is, to my taste, a better way to reduce that potential problem than using sugar. My experiment with it resulted in a taste that was too dulled for my liking.
I seem to be a constant denier here ...
Not at all! Cooking is a very individualistic activity; and I’m happy that you share your perspective, especially when it goes counter to what I’m saying. There are many ways to accomplish a given thing, and I know I don’t know ’em all.
a little goes a long way
If you need to be on a low sodium diet, however, baking soda isn't the way to go to reduce the acidity in tomato dishes. A tiny amount of sugar goes a long way to help a tomato sauce. We were just discussing this very issue at my aunt's funeral. We have a family recipe for spaghetti sauce that belonged to my grandmother. It calls for a pinch of sugar. My cousin makes it all the time, in large batches, to freeze for later use. His ginormous sauce pan holds something ridiculous, I think he said 16 quarts; whatever the large quantity is, he only uses one teaspoon of sugar.
It's nice to know that there's options, though, for helping reduce the acidity of tomatoes. It can bother so many people, causing heartburn and upset stomach.
Fresh!
Fresh tomato sauce and salsas are the only way to go. I grew my own tomatoes before I moved into this apartment, and I was quickly spoiled by the taste of fresh sauces and salsas. Store-bought canned tomato sauces taste metallic to me.
BTW, I'm about 1/3 of the way through the great recipe conversion. I just finished importing 3,000 Indian recipes into Krecipies. Now I can make Chicken Vindaloo without booting into Windows!