Tomatoes — canned or fresh?

20190815_180834aDespite being summer when fresh tomatoes are at their best, I suspect every one of us has canned tomatoes and tomato products in our pantry right now. If you don’t, email me and let me know why not. For the rest of us, we probably have at least some (if not all) of the following: whole tomatoes, diced tomatoes, fire-roasted tomatoes, tomato puree, tomato paste and tomato sauce. These products are the subject of this Cooking Tip.

What is the difference between the different canned tomato products and what are their best uses?

Whole peeled tomatoes – this product is what it says on the label – whole peeled tomatoes. They are usually packed in tomato juice and are great for soup and marinara, where you want the tomatoes to break down. Many feel that their taste is the closest to fresh in-season tomatoes.

Diced tomatoes – these have a firmer texture and hold their shape better. They are generally packed with tomato juice, citric acid and calcium chloride, which helps the tomato pieces to retain their shape. Check the label as they may also have added salt and other seasonings. Use them when you want the texture of the tomatoes such as in salsa.

Fire-roasted tomatoes – these are known for their smoky flavor. Some are actually charred while others are just treated with smoke flavor. The smokiness will vary from brand to brand. Use whenever you want a bit of smokiness in your dish such as chili or salsa.

Crushed tomatoes – The texture of these will vary greatly by brand from thick & sauce-like to chunky. Crushed tomatoes can also have a great fresh tomato flavor. It may be better than fresh as tomatoes that are destined for cans are picked ripe and processed quickly. On the other hand, fresh supermarket tomatoes are picked while still green and hard so they can withstand shipping. They are turned red by spraying with ethylene gas but the flavor is often subpar. Another consideration is that some canned tomatoes are heated to 200-plus degrees (a hot break) while others are only heated to 160 to 185 degrees (a cold break). The lower heat yields a fresher flavor. The problem is that manufacturers do not disclose which method they use. Cooks Illustrated recommends looking at the liquid in the can. If a deep red, it is most likely a hot break while a golden liquid means processing took place at a lower temperature. Crushed tomatoes have multiple uses but are great in pasta sauces.

Stewed tomatoes – these are cut up and cooked with seasonings before packing. Check the label carefully for what seasonings are present. They can be made into a side dish or used in chilis or stews.

Tomato paste – this is made by cooking skinned, seeded tomatoes until most of the water has evaporated. It adds a great savory, umami punch to many dishes.

Tomato puree – this product is made by briefly cooking tomatoes, pureeing and straining them. They have a texture between tomato paste and crushed tomatoes but generally without added seasonings. It is great for adding body and color to your dish but will not have a pronounced fresh tomato flavor.

Tomato sauce – this tomato product is not as cooked down as tomato paste. In fact, it can be made by thinning tomato paste with water. It may be surprising to you to know that almost all tomato sauce is seasoned, usually with garlic and onion. Therefore, just diluting your own tomato paste will not give you the same taste as purchased tomato sauce.
Although all these different products undergo different processing and are best in varying dishes, I would suspect most of us have a variety of them in our pantry. One expert, though, recommends only buying whole tomatoes. Her reasons are as follows:

  1.  You can turn whole tomatoes into almost any other tomato product whereas diced tomatoes cannot be magically transformed into whole tomatoes.
  2.  Whole tomatoes come packed either in juice or puree, giving you more choice. She recommends packed in juice if you want a fresher tomato flavor and packed in puree for a deeper tomato flavor.
  3.  Diced tomatoes have calcium chloride added, which helps the diced tomatoes retain their shape. This may be what you want in a salsa but whole tomatoes will cook down better. Most American whole tomatoes also have calcium chloride added but Cooks Illustrated found that it mostly acts near the surface, leaving the interior very tender. You can find whole tomatoes without calcium chloride but you will need to look at the Italian imports. I looked at the whole tomato products at my normal market. They carried their own store brands, Muir Glen, Hunts and Kuner’s. The only one that did not have calcium chloride was a higher-end store brand. Although my store didn’t carry them, the Cento brand does not have calcium chloride listed as an ingredient. A quick perusal of Amazon showed that if you want to stay away from calcium chloride, imported is going to be your choice.
  4.  No seasoning is added, thus giving you more control over the seasoning in your dish. Tomato sauce and stewed tomatoes are going to have a number of things added to them. If you have looked on your grocer’s tomato shelf, it is getting even harder to find any diced tomatoes without some added seasoning.

What about substituting one type of canned tomatoes for another? For example, if your recipe calls for diced, will your can of whole tomatoes work? It depends – if you want the tomatoes to hold their shape, whole tomatoes will not do this well. If you do not care about the shape/texture, feel free to substitute. Another caution about substituting is to remember that some of these canned products contain added seasonings, which you may or may not want in your dish.
I’m sure most of you have heard that the best tomatoes are San Marzano, the name coming from the region of Italy where they are grown from specific seeds. Today, you can find tomatoes grown elsewhere from the same seeds. Cooks Illustrated did a taste test and found they did not live up to the hype. If you want to read their entire results, here is a link although you will need a membership to view it. For purposes of this Cooking Tip, I will tell you that they preferred Muir Glen, an American brand that was very acidic with a high sugar content. Their runner-up was Hunt’s. Serious Eats agreed that the San Marzano designation wasn’t necessarily a winner. Their preference was for Whole Foods and Trader Joe’s. Finally, just to show you how much an individual’s taste matters, a taste test from TheKitchn put Cento at the top, Muir Glen at #3 and Trader Joe’s last at #9. Who do you agree with? San Marzano or not? Let me know.
Tomato products are one of those pantry staples that are a boon to a cook. With this Cooking Tip, I hope you will take a minute to read labels to ensure you get the right product for your dish. Happy Tomato Cooking!