Canned Diced Tomatoes

From Season 1: Tomato Sauces for Pasta

In late summer and early fall, sun-ripened local tomatoes abound. But fast-forward to mid-February—what are you going to use in your sauce now? The conventional wisdom holds that canned tomatoes surpass fresh for much of the year because they are packaged at the height of ripeness. After side-by-side tests of fresh, off-season tomatoes and canned tomatoes while we were developing recipes for cream of tomato soup, pasta all’Amatriciana (pasta with tomatoes, bacon and onion), and shrimp fra diavolo, among others, we agree. But the many brands of canned tomatoes available beg an obvious question: Which brand tastes best? Having sampled eight brands of canned diced tomatoes, both plain and cooked in a simple sauce, we have the answer.

Sales of diced tomatoes have since come to dominate the category of canned processed tomato products, outselling tomato paste, whole and crushed tomatoes, and tomato sauce and puree, all products that have been around for generations. Depending on the season and growing location, more than 50 varieties of tomatoes are used to makes these products. While tomato varieties are generally not genetically engineered, they are refined for traits that will satisfy growers (yield and harvesting characteristics), processors (ease of skinning and solid-to-liquid ratio), and consumers (color and flavor) alike.

Packers generally reserve the ripest, best-colored specimens for use as whole, crushed, and diced tomatoes, products in which consumers demand vibrant color and fresher flavor. Lower-grade tomatoes are generally used in cooked products, such as paste, puree, and sauce.

Before processing, the tomatoes are peeled by means of either steam or a hot lye bath, which many processors currently favor. Because temperatures in lye peeling are not as high as those in steaming, many processors believe that lye leaves the layer of flesh just beneath the skin in better condition, giving the peeled tomato a superior appearance. Our tasters, however, could not detect specific flavor characteristics in the canned tomatoes based on this aspect of processing.

After peeling, the tomatoes are sorted again for color and the presence of obvious deficiencies, and then they’re diced. After the dice is sorted, the cans are filled with the tomatoes and topped off with salt and filler ingredients (usually tomato juice, but sometimes puree). Finally, the lids are attached to the cans and the cans are cooked briefly for sterilization, and then cooled and dried so they can be labeled. The flavor of a ripe, fresh tomato balances elements of sweetness and tangy acidity. The texture should be somewhere between firm and pliant, and certainly not mushy.

Ideally, canned diced tomatoes should reflect the same combination of characteristics. Indeed, tasters indicated that excessive sweetness or saltiness (from the salt added during processing), along with undesirable texture qualities, could make or break a can of diced tomatoes. If the tasters thought that any one of these characteristics was out of whack, they downgraded that sample. In fact, two of the eight brands in the tasting were deemed to have major flaws in both flavor and texture that landed them in the lowest echelon of the ratings.

The downfall of the lowest rated brand of the eight was saltiness. It had a good 50% more salt, a characteristic that tasters easily detected and didn’t appreciate. The other brand that tasters relegated to the “Not Recommended” category, suffered from a triple whammy of flavor and texture problems, according to our tasters. First, it was the only product in the bunch that was packed in tomato puree, rather than the more common tomato juice. This led to complaints about the flavor, which some tasters perceived as “way cooked,” “like candy,” and “ketchupy.” By comparison, the thin, watery juice in which the other canned diced tomatoes are packed tasted lighter and more natural. Puree is heavier and pulpier than juice, and must be heated longer to achieve its specified concentration. In short, more cooking equals less freshness.

This brand was also the only one in the lineup that didn’t include calcium chloride among its ingredients. The calcium in this compound helps the tomato pieces maintain a firm texture by stabilizing the pectin network in the tomato tissue. Because calcium is divalent, that is, it has an electrical charge of +2, it acts as a bridge between two long chains of pectin, in effect bonding them together. Based on our results, the absence of calcium chloride made a difference, with tasters describing these tomatoes as “mealy,” “very broken down,” and “squishy.”

Oddly, no one flavor profile dominated. The three highly recommended brands, displayed a range of flavor characteristics. What link these three brands, then? Well, it’s more about what characteristics they don’t have than what they do. None of them exhibited major flavor flaws, the likes of which landed some other brands down in the ratings. The three winners were neither too sweet, nor too salty. Likewise, they tasted neither bitter nor metallic.

On the topic of winning texture, however, tasters were in accord; they frowned on mushy canned tomatoes.