Tomatoes too Acidic?

Sunni's picture

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.

Update 2/11: As has been mentioned in the comments, some individuals who have heartburn actually have too little stomach acid, rather than too much. Please see this short post by an M.D. on the subject, and for an easy test of stomach acid that can be done at home.


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!

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. :)

Foods high in acid can

Foods high in acid can affect people in bad ways. For me, they cause the lining of my bladder to get inflamed! Having discovered this a month ago, I've been going without tomatoes, which is a total bummer. If I can do anything to be able to consume them in any way, I will, even if it means changing the flavor a little. Tomatoes are in EVERYTHING and not being able to eat tomatoes has made it so that I can't eat a lot of my favorite foods.

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.

I hear that sugar doesn't

I hear that sugar doesn't reduce the acid, and only hides it. Is this true. I have bad acid reflux, so my main goal is to reduce the acid in the sauce, not mask it.

Today I am making a pizza sauce. I don't mind a little sweetness in pizza sauce, so I am adding a little sugar and a little baking soda.

I think it does.

I’ve been researching this question off and on since it was posted here, but I haven’t come up with what I consider to be a definitive answer. There are many pages that address the issue very specifically, usually demonstrating the reaction between concentrated sulfuric acid and damp sugar.

We’re a long ways from pure controlled chemistry here, but it seems logical to think that some reaction is taking place between the tomato acids and sugar added to the dish. With all the other molecules in there, though, it’s tough to say exactly what is going on.

All that said, I’m not sure that the acid from tomatoes is necessarily the source of your problem. Stomach acids themselves are much stronger than the acid in tomatoes; if tomato sauces bring reflux for you, perhaps the problem is garlic, or onions, or the general level of spices in the sauce.

Sorry I couldn’t be of more help.

Added Ignorance

Never one to shy away from adding to the general level of ignorance on a subject, I just want to point out that in my period as a subscriber to Dr. Jonathan Wright's medical newsletter I found numerous references to insufficient stomach acid as being a problem that was often diagnosed as just the opposite. It seems counter intuitive, but I mention it simply to spur investigation by those who might be so afflicted. Like the decades-long thing with ulcers, sometimes the solution is vastly off track from our beliefs.

(Boy do I miss good tomatoes. I haven't had one in... well it seems like decades now.)

- NonE

Yes indeed!

This was a constant struggle during my nursing career, especially with my hospice patients. Very few of them were eating anything like an optimal diet, and most ate almost no fruits or vegetables. They often were taking chemical medications that damaged their appetite and ability to digest. It was no surprise to find that many had active "indigestion" and even reflux, but it was not likely due to "too much acid," but too little and other disturbances, but they took "Tums" by the handful all too often.

One of the greatest causes of reflux is overweight, for starters, because the abdomen presses against the diaphragm - causing pressure upwards just where the valve for the stomach passes through, which can adversely affect its ability to hold back stomach contents.

Another common cause for reflux is poor stomach emptying, which can be caused by many things including chemical medications - especially any sort of pain medicine. Another contributing factor can be poor teeth and rapid swallowing of large amounts of poorly masticated food. The stomach can't manage a lot at a time, so if it can't pass through the lower valve to the intestines, it backs up. Combine that with overweight and you've got a real problem.

Unfortunately, the response of most people is to take more medications that neutralize acids, which further slows the digestion process and often increases the discomfort.

This is why acid reducing medications should only be taken if tests indicate actual excess stomach acid, period. Otherwise, evaluate the situation and see if one of the other causes might be at the base of the problem instead.

Please note, however, that if you DO have a reflux episode, it is very important not to let the acid stomach contents just sit in your throat! Rinse with plenty of clear, cool water and then eat a soda cracker or part of a slice of bread. Rinse that with some more water and then do not attempt to eat anything at all until you become truly hungry.

Hope this helps.

Reducing acidity

To reduce the acidity, you need to add something that is alkaline in the sauce. If your sauce isn't vegetarian, you can add a bone (for example a soup bone, chicken bone etc).

If your sauce is a seafood tomato sauce, you can also add a sea shell as you cook it. A clam shell for example is mostly composed of calcium carbonate.

Another option is to rinse an egg in cold water to clean it, and hard boil it in the tomato sauce. The calcium carbonate in the shell will help neutralize the acid.

The vitamin C in the tomatoes will react with the calcium carbonate and produce some calcium citrate that can easily be absorbed. With the egg shell and clam shell you will also get some magnesium citrate.

acid from canning

my need to reduce the acid comes from my very own canned tomato soup. during the canning process we have to add lemon juice to tomatoes, but this results in a very lemony tomato soup. blaaa! i've tried all kinds of things, but am working thru the entire batch and haven't found a good solution. today, i'll try baking soda. thanks for the suggestions.

Acid from canning

This is also my problem. I canned delicious spaghetti sauce with garlic and green peppers. I had to add roughly 1T of lemon juice per quart to preserve the sauce. I just opened my first jar, and it is horrible! Do you all think that the sugar and baking soda will mask the lemon flavor as well as reduce the acidity, or what could help fix this problem? THANK YOU!

Possible help

According to a University of Minnesota document on canning tomatoes, adding a bit of sugar can help offset the acid tone in your sauce. I doubt that it’ll do much about the lemon flavors, however.

I was thinking that citric acid might be better for canning, since it won’t have the citrus elements that lemon juice adds to tomato sauce. Sure enough, that same article lists citric acid quantities for pints and quarts. (It also explains why vinegar isn’t always a good substitution.)

Home grown tomato sauces don't bother me but store bought do

I was wondering if anyone has experienced the following. I typically get heartburn with store bought tomato sauces (tomato paste, tomato sauce, spaghetti sauces, etc). However, last summer, my wife made up some sauce from the Roma's in our garden and no heartburn at all. Could someone provide some insight into this? I'm fairly certain my wife doesn't want to make our own tomato sauces all of the time. :)