My tomato sauce is coming out great, lots of flavor, especially after I was able to reduce it following the tips here

However, it is still slightly bitter. What causes a tomato sauce to have a (in my case, slight) bitterness and how do you get rid of it?

Is there an anti-bitter technique that is commonly used.

  • Do you start with fresh tomatoes? May 16, 2011 at 21:22
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    I find canned tomatoes do have an off taste, more bitter than anything else. Maybe you should change the brand. My teacher recommends plum tomatoes. A colleague recommends whole canned tomatoes. I recommend investigating a lot of different brands... Go with fresh mature tomatoes if you can, canned whole plum tomatoes if you can't. May 16, 2011 at 21:40
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    Do you fry garlic for the tomato sauce?
    – user4697
    May 16, 2011 at 22:33
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    @Matt: Perhaps you burnt the garlic? That tends to impart bitterness, I've learnt.
    – user4697
    May 17, 2011 at 7:05
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    I have always used chopped tinned tomatoes. If using the tomato sauce as a base for pasta and meat dishes i.e. a simple bolognese or lasagne, many authentic italian recipes opt for finely chopped carrot within the ingredients. The addition of something naturally sweet brings out the flavour of the the tomato.
    – kathryn
    Sep 27, 2013 at 9:48

8 Answers 8


A few things can cause tomato sauces to become bitter:

  • Overcooked spices. Both basil and oregano can become bitter with long simmers. Add them near the end of the process.
  • Under-ripe tomatos. Store bought tomatoes are often picked green and ripened in the store. These tomatoes make less sweet sauces (which may be contributing).
  • Cooking in an aluminium pan. Aluminium reacts with the acid in the tomatoes and adds an off-putting flavour.
  • Seeds/skin in the sauce. Both seeds and skins can be bitter.

You can improve a bitter sauce by adding a small amount of baking soda (or salt), and something sweet (but not too much).

  • Thank you: I love tomato sauces, they're versatile, tasty, and healthy too. May 16, 2011 at 21:45
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    If you have a machine to separate skins and seeds from fresh tomatoes, and you hae discovered that you can put the skins/seeds through again and get another jolt of sauce (thicker than what you get the first time through), do not put them through a third time - that will bring the bitterness from the seeds into the sauce. Jun 6, 2011 at 15:01
  • Maybe one should also add "undersalted"? Feb 5, 2018 at 10:47

In the same vein as Bruce's answer, try using plain diced tomatoes and adding the spices yourself instead of using the "italian" variety. Also, If you use garlic in your sauce too that might sweeten it a little and counteract the bitterness without adding sugar.

  • 2
    Also consider roasting some garlic for your sauce: I often will use roasted, lightly fried, and granulated garlic in the same sauce (for extra garlicy dimensions). The oven-roasted garlic is sweet, and adds incredible depth. May 18, 2011 at 2:58

Skin the tomatoes but keep them whole in the sauce 'til cooked. They will break down when they're ready. Seeds are bitter. Also I add a couple of sweet bay leaves.


I've found the following to make tomato sauces bitter:

  • Tomato seeds
  • Underripe tomatoes
  • Burnt garlic

Usually, adding sweetness helps somewhat, although letting the garlic get too brown, let alone burn it, can hardly be corrected for. Some things I've found to help:

  • Extra carrot
  • Brown sugar

You can add half a carrot to the sauce and remove at the end. The carrot absorbs the acidity :)

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    It's not so much absorbing anything as the sweetness from the carrots help to mask it. Personally, I add a fair bit of carrot to my tomato sauce, but you need to cook them down before adding the tomatoes as the acid will preserve their firmness. You can also add a little bit of sugar to help balance things out if you don't have the time to finely chop (or grate) carrots and cook them down first.
    – Joe
    Sep 27, 2013 at 12:26
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    Just grate half a carrot into the onion and garlic that you saute, prior to adding canned San Marzano tomatoes. There is no extra time involved and the sugar from the carrot balances the acid from the tomato nicely.
    – moscafj
    Oct 15, 2013 at 12:42

I find the seeds of fresh tomatoes to be the cause of the bitterness. Try to remove as many seeds as possible by squeezing tomatoes after blanching and peeling. Its hard to get them all but that is okay. Then a bit of cane sugar. This will balance the flavors a bit but some bitterness is good as it is a flavor of fresh tomatoes.


I can’t answer the first part of the question: why tomatoes are bitter (and it looks like a few people already have anyway).

I use three methods for sweetening tomato sauce. The first two you can use with anything: red current jelly and port (port is my favourite cooking ingredient because you can use it in place of red wine in most cases, too).

The third I came across online (can’t find the source), but basically, put your tinned tomatoes (or whatever) on the hob and then cut a brown onion in half and drop that in the sauce. Then cook it for a long time (maybe two hours). At the end, just take the onion out and chuck it.


For being more precise:

Tomatos are acid! This is the characteristic of tomatos. And this is also the reason of tomato success. Thanks to this quality tomato makes edible all other acidless food. Acidity produces a strong salivation that makes easiest the first approach with food you eat, clean palate and give the wish to eat again at once. But also acidity makes bite fairly bound in mouth up to bottom.

In fact before tomato, acidity was taken from citrus and fruits.

Of course acidity makes food bitter. This is the only reason of bitterness of tomato sauce.

There are two main ways we use in Italy to remove that bitterness:

  • a pinch of sugar in the sauce while cooking it. This is the main and traditional one!
  • a pinch of bicarbonate of soda.

The garlic and also triturated carrot are other ways but alter the sauce. I don't advice those for genuine tomato sauce.

I hope you have a better understanding of bitterness and I could help you validating what Bruce said about how to remove it.

The Italian cooker ;)

  • About garlic I said that because if your tomato sauce has started with garlic you're at middle way to reach your target for sure but what if your tomato sauce is made from onions? That's why I raise objections to garlic solution. ;)
    – soneangel
    Jun 6, 2011 at 10:38
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    Sourness is based on acidity. Bitterness involves completely different taste receptors and compounds which are common in plants and herbs.
    – Aaronut
    Jun 6, 2011 at 21:27
  • @Aaronut well I missed understand the taste topic. But they are confuse as well. Because the baking soda and something sweet react with sourness, not react with bitterness! ;)
    – soneangel
    Jun 7, 2011 at 7:51
  • Baking soda would reduce acidity, sugar would add sweetness (that masks sourness and bitterness). None of those will "react" with bitterness or sourness. If you have burnt garlic in the sauce you still have it, no matter how much sugar you add.
    – nico
    Sep 7, 2011 at 22:42

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