Before You Reach for a Can of Diced Tomatoes, Consider This

February 15, 2017

Diced tomatoes promise neatness and convenience: There are no juice-filled water balloons to crush or snip or coax into softness, slowly and patiently, on the stove.

But here's an ironic surprise: Diced tomatoes—which you'd expect to break down much faster (since, duh, they're smaller)—are actually packaged to keep their shape. Those diced tomatoes you bought to save time are making achieving a smooth, homogenous sauce harder (and slower). Those liars.

These are from cans of whole, peeled tomatoes—and they're going to break down beautifully. Photo by James Ransom

Food science expert (and whole canned tomato evangelist) J. Kenji López-Alt doesn't call for diced canned tomatoes in his book The Food Lab because...

Calcium chloride is a common food additive used to keep canned fruits and vegetables firm; to coagulate soybean curds into tofu; and to ensure crisp pickles without the hassle of a lime-water soak (lime being another source of calcium). In the case of diced tomatoes, the addition of calcium chloride means they'll retain their bite and shape even as they're cooked.

So, the rule of thumb

Diced canned tomatoes are good if you're making a slow-cooked dish but you still want distinct tomato pieces—maybe in chili, stew, braises, or, depending on your preferences, shakshuka.

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But whole or crushed canned tomatoes are likely the better choice for any sauces, soups, or baked pastas where the tomatoes should melt down completely.

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Top Comment:
“I'll have to start keeping whole canned on hand the way I do diced tomatoes now--I love chunks of tomato but the other half prefers things smooth. Thanks for the advice!”
— Kayleigh

If you do find canned diced or chopped tomatoes (like Pomì) that don't list calcium chloride as an ingredient, however, you can use them as you would their whole brethren without worrying that they'll retain their cube-like shape no matter how long they're simmered.

As for avoiding the mess of crushing tomatoes (which, if you're wearing an apron, can be a satisfying tactile experience), we've got some recommendations below; Kenji pokes a hole in every tomato before he squeezes out to direct the spray of juice.

a fresh tomato post-script

While canned tomatoes sure are handy—and we on the East Coast are pulling our reserves from pantries (and bookshelves and bedroom closets)—, let me offer just a brief reminder of the fresh (!) summer tomatoes we can look forward to...

How's that for a little sunshine in the middle of February?

When do you used canned diced tomatoes versus whole or crushed? Tell us in the comments below.

See what other Food52 readers are saying.

  • FrugalCat
  • Robert
  • Kim
  • Big Pot
    Big Pot
  • melissa
I used to work at Food52. I'm probably the person who picked all of the cookie dough out of the cookie dough ice cream.


FrugalCat May 26, 2020
I buy the diced tomatoes when I want them to keep the diced shape- salsas, queso, etc. I like the fire-roasted ones, as I can't do that myself (no gas stove).
Robert May 16, 2018
Seems like all you can buy are diced tomatoes lately. Like you, I prefer whole peeled.
Kim March 23, 2017
How fascinating! I never really thought about the other ingredients changing the texture of the diced tomatoes. I tend to be a whole tomato gal because you can then just go and change the texture by blending etc.
Big P. March 22, 2017
I always thought about Pomi in terms of relative salt content, but I just checked the nutrition facts on my just-purchased Muir Glen Organic diced tomatoes and there's the calcium chloride...something to consider!
melissa February 17, 2017
mind = blown!
Samantha V. February 16, 2017
But I LIKE tomato chunks in my tomato sauce. I used diced not to cook faster, but to have perfect sized chunks. I usually combine them with crushed or sauce to get a combination of textures.
Kayleigh February 15, 2017
Oh my gosh, that tomato upside-down cornbread looks exceptionally delightful. Thanks for giving me a great idea for when the summer tomatoes start rolling in... and as for the article in general, I have to say, this is eye-opening and will come in handy in the future. I'll have to start keeping whole canned on hand the way I do diced tomatoes now--I love chunks of tomato but the other half prefers things smooth. Thanks for the advice!
Liz D. February 15, 2017
I used diced as that's what I usually have on hand--if I want a smoother texture, I whiz them to puree with a stick blender
Donna H. February 15, 2017
La Pavoncella (sp?) are my favourites, nice balanced flavour, they break down nicely. Now I understand why when I added a can of diced Aylmer tomatoes to my cabbage rolls, cooked for 8 hours in slow cooker, they looked exactly the same as when I put them in. Thanks for the information!
Smaug February 15, 2017
Not only that, the higher quality tomatoes are generally packed whole. I usually keep an open can of diced tomatoes (in a plastic jar) in the refrigerator for convenience in dishes that may require just a spoonful or two. Speaking of fresh tomatoes- it may not look like it outside, but it's time to start your seedlings for this year.