Plum tomatoes are the go-to tomato for sauces, pastes, and any recipe where you want thick, rich tomato flavor without excess water. Their dense, meaty flesh and low seed count make them fundamentally different from the round slicing tomatoes you’d put on a sandwich. That meatiness is exactly why Italian cooking has relied on them for centuries, and why they’re the best choice for everything from a slow-simmered marinara to homemade salsa.
Why Plum Tomatoes Excel in Cooking
The key advantage of plum tomatoes is their flesh-to-juice ratio. Slicing tomatoes are full of juice and seeds, which means they need to cook down much longer before a sauce thickens. Plum tomatoes are meatier than they are juicy, so they reduce faster and produce a richer, more concentrated result. This lower moisture content makes them ideal for sauces, salsas, tomato soup, bruschetta, ketchup, and purees.
That same density is why plum tomatoes are preferred for canning and preserving. When you’re putting up jars of crushed tomatoes or tomato paste, you want the maximum amount of usable flesh per tomato. Less water means less time cooking it down and a better final product.
Plum tomatoes also work well roasted. Cut them in half lengthwise, drizzle with olive oil, and roast at high heat until they caramelize. The low moisture content means they concentrate and sweeten rather than turning into a puddle on the sheet pan. Toss roasted plum tomatoes with pasta, blend them into soup, or eat them straight off the tray.
Roma vs. San Marzano: Two Popular Varieties
Most plum tomatoes you’ll find at a grocery store are Romas. They have high sugar and acid levels, which makes them more flavorful than standard slicing tomatoes. Romas are versatile, affordable, and widely available year-round. Their firm texture holds up well in salsas and bruschetta, where you want distinct pieces that don’t dissolve into mush.
San Marzano tomatoes are the premium option. Grown in volcanic soil near Mount Vesuvius, authentic San Marzanos carry a D.O.P. certification (a European quality designation, similar to how Champagne can only come from one region in France). They’re longer and pointier than Romas, with only two seed chambers instead of the typical three or four. The flavor difference is notable: San Marzanos have milder acidity, making them sweeter and jammier. They’re the traditional choice for Neapolitan pizza sauce and are widely considered the best tomato for a smooth, balanced marinara. You’ll mostly find them canned, sold whole or filleted.
Nutritional Profile
Plum tomatoes share the strong nutritional profile of all red tomatoes. A 100-gram serving (roughly one medium plum tomato) provides about 14 mg of vitamin C, 237 mg of potassium, and a meaningful amount of vitamin A. They also contain folate and natural fiber in the form of pectin, which makes up about 7% of a tomato’s dry matter. All of this comes with very few calories, since tomatoes are mostly water even in their denser plum form.
The standout nutrient in plum tomatoes is lycopene, the pigment that gives them their deep red color. Lycopene is a powerful antioxidant, and tomatoes are the single largest dietary source of it for most people. What makes plum tomatoes particularly valuable here is that they’re so often cooked, and cooking dramatically increases the amount of lycopene your body can absorb. Research from Cornell University found that heating tomatoes boosted the beneficial form of lycopene by 54% to 171%, depending on cooking time. The form of lycopene that your body absorbs most easily also increased by up to 35% with cooking. So a homemade tomato sauce made from plum tomatoes delivers significantly more lycopene than eating the same tomatoes raw.
Heart and Prostate Health
The lycopene in tomatoes has been linked to two areas of health that get a lot of research attention: cardiovascular disease and prostate cancer. A large prospective study published in BMC Medicine followed nearly 3,000 men at high cardiovascular risk over about six years. Those with the highest lycopene intake had a 54% lower risk of prostate cancer compared to those who consumed the least. The protective effect became significant at intakes above 4.9 mg per day, which is roughly equivalent to 175 grams of tomato (about two medium plum tomatoes).
Cardiovascular disease and prostate cancer share several underlying risk factors, including chronic inflammation and oxidative stress. Lycopene appears to work against both of these processes, which is why researchers believe it may be especially protective for men who already have elevated heart disease risk. While these findings are observational and don’t prove cause and effect, they’re consistent with a broader body of evidence supporting lycopene-rich diets for long-term health.
Adding a small amount of fat, like olive oil, when cooking tomatoes further increases lycopene absorption, since lycopene is fat-soluble. This is one reason why the classic Italian combination of tomatoes, olive oil, and garlic isn’t just delicious but also nutritionally smart.
How to Peel and Seed Plum Tomatoes
Many sauce and soup recipes call for peeled, seeded plum tomatoes. The standard method is simple: score a shallow X into the bottom of each tomato, then drop them into boiling water for 10 to 15 seconds. Watch for the skin to start shrinking back and curling at the edges. Transfer the tomatoes immediately into a bowl of ice water to stop the cooking. Once cool, the skins slip off easily with a paring knife. If done correctly, no flesh pulls away with the skin.
To seed plum tomatoes, cut them in half lengthwise and gently squeeze. The oblong shape of a plum tomato makes this easier than with round varieties, since the seeds are concentrated in a narrow channel. Save the seeds and juice if you want extra liquid for soups or stocks. For a more precise prep, quarter the peeled tomatoes and cut away the seeds and white membranes with a paring knife.
Picking and Storing Plum Tomatoes
A ripe plum tomato is fragrant at the stem end and gives slightly when you press it. It should feel heavy for its size, with smooth, taut skin and no soft spots or wrinkles. Color alone isn’t always reliable, since some varieties are ripe at different shades, but for standard red plum tomatoes, look for a deep, even red.
If your plum tomatoes aren’t fully ripe, set them stem-side up at room temperature (around 70°F) until they soften and develop their aroma. Once ripe, move them to a cool spot. You can refrigerate fully ripe tomatoes for up to two to three weeks, but the tradeoff is real: cold storage can make them mealy and muted in flavor. For the best taste, always bring refrigerated tomatoes back to room temperature before using them.