Lasagna, shepherds pie, spaghetti sauce... all of my meals with tomato-based sauces have an acidic bite to them. Is it the canned tomato products causing that? How do I mitigate that?
"Change tomato brands and see if that helps."
No, that is not an option. I'm a ranch cook well off the beaten path. I do not do the shopping. I provide a list of what I want/need, and sometimes I get that, sometimes I get something else.
What's causing the acidic bite? How do I tame that bite?
The acidic "bite" is caused by acids in the tomatoes.
The easiest way to avoid it is to add some sugar to the sauce. How much to add is a personal taste thing and depends a bit (I find) on what is also in the sauce, but a teaspoon or two per can is usually plenty. The ingredients in the sauce also play a role as some have different levels of sweetness to them too. For instance, regarding onions, you could use red onions (sweet) or a yellow or white onion (less sweet), and if you caramelize them (rather than just sweat them off), this can alter the taste perception. Other ingredients (e.g., garlic, various types of peppers, and sometimes carrots are common in mine) might also play a role, so test out different ratios and see how you go.
You can't avoid the acid totally; there will always be some acid in tomatoes. There are low-acid tomatoes such as the Roma variety. Some brands of tomato producers use these in canned tomatoes, but as you seem to not be able to specify, this won't be much use to you.
The "bite" is indeed acidity as you identified. The surest way to reduce acidity is with a base. Add a small amount of baking soda to your canned tomato product to neutralize it. Start with a very small amount -- Serious Eats recommends 1/4 tsp per 28oz can, but I would start with even less.
I'm simmering some of these sauces for 5-6 hours
Contrary to popular myth that "cooking tomatoes for a long time" will make them less acidic, it actually does the opposite, the longer you cook tomatoes the more sour they become
Citric acid (primary acid in tomatoes) has a decomposition point of 170C and a boiling point of 310C. It doesn't evaporate or decompose while being cooked.
Malic acid (second most plentiful acid in tomatoes) has a decomposition temp of 280C and boils a long time after that. Doesn't leave the dish as you cook it.
Water will however leave the dish. The longer/thicker you simmer the sauce down the more concentrated the citric acid/malic acid become (per weight of sauce) which increases how sour it tastes. If you reduce the water in your dish by 1/2 you will ~ double the acidity.
*Note I know that a very small percentage of the acids probably evaporate with the water due to some chemistry term I don't remember.. But it occurs at a much much slower rate than the evaporation of water.
*Note 2 halving the amount of water in a dish doesn't double the acidity. The amount it increases depends on what percentage of your dish is water... As tomatoes are 95% this is approximately correct for the first 2 times you have the amount of liquid.
IE a shorter simmer time. Shorter cook time means less water evaporates, so the the acids inside of the tomato are less concentrated. This does mean that the sauce won't thicken well, and nor mix with the oils. It loses a lot of flavor.
Adding beef broth, vegetable broth etc... dilutes the acid making it less sour. I do not recommend this. Also this doesn't work if you simmer it longer to compensate for the extra liquids.
Coca-Cola/Pepsi are very acidic (due to carbonic acid from carbonation). They have a PH of 2.5. For your reference, vinegar and lemons have a pH of around 2.2. But you don't realize that your soda is really acidic (and dissolving your teeth) because of how much sugar they dump into your soda. Your sweet taste buds override your sour taste buds. I don't know the exact ratio how much sweetness you need per unit of sourness, but a I know that a little bit of sugar goes a long ways.
Why does this work? I am not entirely certain. I think it is because we are sugar junkies by nature. (probably for survival reasons, calories were once hard to come by).
Sweetening the sauce is how most people deal with the acidic bite that comes from tomatoes. Traditionally this is done with minced carrots or carrot juice. but you can also do it with sugar, or with sweet onions. I like sugar, as it's easy to add in as a fixit... While you have to intentionally add in carrots or use sweet onions.
Use tomatoes that aren't as acidic. Probably not an option for you, as you aren't the one doing the shopping. If you are I recommend doing research on the tomatoes for sell at your local super market to find the least acidic option. Google is your friend there.
A spoonful of sugar helps the medicine go down!
In the most delightful way
But seriously, just add a little sugar. It works really well, and barely effects the flavor profile of your sauce. No one will know. It is the secret ingredient in a lot of restaurants' tomato sauce (in the US).
I think it is likely that the overly acidic taste is due to the brand(s) of canned tomatoes you have been given. Many cans of tomatoes (usually the cheaper ones) have Calcium Chloride added to them, and Citric Acid too. Calcium Chloride especially can affect the flavour and both serve as a signpost for lower quality ingredients. A high quality brand will have 100% tomatoes, maybe with a tiny bit of salt. Check out the Ethan Chlebowski YouTube video "Are San Marzano Tomatoes actually worth it?" for more on this and a few other factors.
When using the more acidic types of canned tomatoes, I do think sweetness is about the only way to balance it. Doesn't have to be granulated sugar though. It might not be so readily available, but as an example, I like to add a bit of Korean gochujang to my tomato sauces as it gives both spice and a complex sweetness.
Joe's Sicilian technique with carrots etc is a great one too - dice down small, sautée until very soft and sweet, almost a paste. Blend together if you like. Other techniques like letting the sauce cook down on its own for longer don't work for me though.
NB for those in EU/UK, I think Calcium Chloride is not allowed, just the Citric Acid.
As the other answers state, this is caused by the native acidity of tomatoes. The best way I've found to deal with this without having to add other ingredients, is to enhance the richness of the tomato by cooking it more. If it is reduced more, the flavour profile slowly shifts from tangy towards umami and rich. The acidity won't disappear, but it will shift the focus away from it the longer the sauce is cooked.
This will change the timing of when you add other ingredients like flavourings or fresh herbs though, so make sure to adjust for that.
If you don't have any additional time or you already cook it for as long as you can, try one of the other answers. I personally have had good experiences with baking soda.
Do you use onions in your tomato sauce recipes? If you use a good amount of onions and saute them for a long time (~15mins) so as to caramelize a bit, they will add a natural sweetness to the sauce which will counteract the acid of the tomatoes. I have also seen recipes that suggest adding grated carrot to tomato sauces as another source of natural sweetness.
I have a different perspective on this issue. Hope that it is useful. I'm in my 60s, and it seems to me that canned tomato products have gotten less flavorful and more acidic over the years. It could just be me. I checked with ChatGPT. I don't think its just me: "Yes, tomato growers and processors have historically selected higher acid varieties to help reduce spoilage before processing." I belong to the long and slow school. My Sicilian grandmother used to cook her sauce for 4-5 hours on slow simmer. My father regularly made this recipe as well. It remains my standard for what a tomato-based sauce should taste like. I've almost never had a comparable sauce in the US, only a few times on Italy visits. If using canned tomato ingredients or paste myself, I at least let it go for an hour or so, and I can always tell the difference with an "undercooked" sauce. I think the operational chemistry is a little different than others have suggested here and dependent on the ingredients. My grandmother's sauce is meat based (as are most of mine) and my guess is what's happening is that the hot acid over time works on the meat (or whatever else is in the sauce), breaking it down and releasing flavor into the sauce, and at the same time neutralizing the acid. Bearing that in mind, you may still not always have time as a ranch cook for such involved preparations. Other options: Yes sugar is an effective mask and quick fix, but doesn't change acidity. Lemon juice bad. Lemonade good. Garden grown or farmer's market tomatoes are great in season, and fantastic for "fresh" tasting sauces. This is only good for a couple of months per year though, and almost never available in standard supermarkets. San Marzano tomatoes are excellent, but quite expensive. Starting to show up in 'regular' supermarkets, but you can reliably get them on the internet. You have to ask how much you are willing to pay to have a meal you enjoy versus one you don't, or as a professional how much to have delighted customers versus 'meh' customers. If it were me (it isn't, over my pay grade here), and I wanted to try this out, I'd start with a small personal investment to try it for myself, and then if that worked try a pilot of the 'new recipe' for a few customers to see if they can tell the difference. If it's a big hit figure out what you might cut back to stay within a fixed budget.
At the moment all of the options are for balancing the acidity of the tomato sauce by adding things to them like baking soda (to reduce the acidity itself) or sugar/butter (to change the flavour profile).
Your problem is indeed acid from the tomatoes, but there's another option - just cook the sauce for longer! After about two hours, you should find almost no acidity at all in the taste.
You might (depending on the sauce) need to add a splash of water during cooking to stop it drying out and burning, but just cooking it for longer will solve your problem.
In addition to the already mentioned options of adding sugar or baking soda, I also find that oregano helps balance excessive acidity of tomatoes. Other than my (admittedly subjective) experience I can't offer a lot of facts to back this up, but oregano is considered an alkaline herb so the effect may be similar to that of baking soda (though probably not as pronounced). This is of course only an option if you don't already have some oregano in the recipe to begin with (unless you don't mind that the taste will go a little bitter if you add more oregano).
