Why Canned Tomatoes Always Come Pre-Cooked

Canned tomatoes, whether whole, crushed, or pureed, are a regular in almost every cupboard. They may not last as long as other canned foods because of their high acidity, so canned tomatoes still hold peak flavor for about 18 months — this should still be plenty of time to use them. Although many tomatoes are actually placed in the can fresh, they still end up getting a bit of a cook. For some insight as to why, we reached out to Spencer Lane, the business and brand manager at Contadina.

Lane says that after harvesting at peak ripeness, whole tomatoes are washed, peeled, packed in tomato juice or puree (diced or whole), then packed in cans. "The cans are sealed and heated to make them safe to store and lock in flavor and nutrients," he says. "The cooking is not extensive, but just enough to soften the tomatoes and stabilize them for storage." Canned tomatoes must be sterilized, so they'll be shelf-stable and sealed off from harmful contaminants. 

Depending on the style of tomato, more cooking may be involved. Crushed tomatoes are partially cooked before canning to achieve a consistency similar to a sauce. Pureed tomatoes are cooked completely and then strained to create a thick, fully concentrated liquid. Lane says, "Contadina's tomato paste is made by slowly simmering vine-ripened Roma tomatoes until most of the water evaporates, creating a concentrated product with a deep, rich flavor."

Processing can actually help concentrate the tomato flavor. "The heat treatment gives canned tomatoes a deeper, more robust flavor than many fresh tomatoes, especially those out of season," says Spencer Lane. "However, the texture is softer than fresh tomatoes, making canned varieties ideal for cooked or baked dishes."

While you can eat canned tomatoes right out of the can, they're usually only used in cooked recipes and not generally recommended for dishes that use raw, uncooked tomatoes, like a caprese or any tossed salad. Using canned, whole tomatoes is one of the best tips for making homemade pasta sauce and you don't have to bother with peeling fresh tomatoes. You can even skip the extra chopping prep required and go right to crushed or pureed tomatoes. All you need for a simple red sauce is some sautéed onions and garlic, a can of tomatoes of your choice, a bit of tomato paste, and herbs and spices mixed in to your liking.

When using them in recipes, you can cook your canned tomatoes until caramelized before you add them with the rest of the ingredients for a deeper, sweeter flavor. Lane recommends using canned tomatoes over fresh in long-simmer sauces, stews, and soups, noting that tomato paste is a great way to intensify the flavor of your dishes. He says, "Outside of peak tomato season in August and September, fresh tomatoes can be hard to come by or lack flavor, so canned tomato products are a great substitute during the fall and winter months."