How we tested
Fresh tomatoes charred over an open fire possess a sweet, smoky depth that plain tomatoes can’t match. We wondered if canned versions could meet that ideal, so we gathered three nationally available diced fire-roasted tomato products to find out. They certainly all looked the part, with char-flecked tomatoes in every can. But flavor told another story in the case of one product which tasters found had faint smoke flavor at best. While the tomatoes from another manufacturer added decent smokiness to our Cook's Illustrated Red Chile Salsa, they fell to the bottom of the group for having artificial flavors and chewy skins. Our favorite of the three tasted aggressively smoky when sampled plain, but in the salsa that intensity mellowed, providing a smoky background flavor that tasters appreciated. These tomatoes also won favor for having a sweeter, fruitier flavor than the other two products.
To account for the differences, we first looked to processing, but we didn’t get far: One maker told us that it passes the tomatoes under and over a gas-powered flame while another only passes them over the flame. The third manufacturer wouldn’t disclose its method. So we looked to the ingredient lists for answers.
The tomatoes from one company, flagged for weak smoky flavor, contain—no surprise—just tomatoes, tomato juice, salt, citric acid, and calcium chloride (a common ingredient in canned diced tomatoes for firmness). Two other makers bolster those base ingredients with additional seasonings, including onion and garlic powders, yeast extract (which boosts umami), and “natural flavoring,” a catchall phrase that can include any number of naturally derived additives. While liquid smoke does qualify as a natural flavoring, a representative from one maker told us that the company doesn’t include it, and another manufacturer would not divulge if it does. Whether it’s an undisclosed natural additive or a secret in the processing method we weren’t made privy to, both manufacturers obviously found a way to boost smoky flavor. And without the textural drawbacks and off-flavors of the tomatoes by one maker, we had a clear winner.
Still, we had one last question: Is that smoky flavor significant enough to make fire-roasted tomatoes worth using instead of plain diced tomatoes? For two final tests we compared our favorite fire-roasted tomatoes to our favorite canned plain diced tomatoes in both our Cook's Illustrated Red Chile Salsa and our Simple Beef Chili with Kidney Beans. While the difference was less noticeable in chili, likely because of the competing spice flavors, the salsa made with fire-roasted tomatoes was the clear winner, with a complexity and background smokiness that put it above the plain-tomato version. Our winning tomatoes also gave the salsa a markedly more appealing appearance that was a deep brick red compared with the almost candy-apple red color of the version with plain tomatoes.
While fire-roasted tomatoes won’t add much to already complexly flavored recipes, when we want an easy way to add subtly caramelized, smoky tomato flavor to simple dishes like our salsa, we’ll reach for a can of our winner.