Most grocery stores carry canned Roma and San Marzano tomatoes. But have you ever wondered about the difference between the two?
Look for tomatoes in the canned food aisle at the grocery store, and chances are that nine out of ten cans will be Roma tomatoes, the best known and most widely used tomato variety for canning.
This one other can?
Those are San Marzano tomatoes, the Ferrari of canned tomatoes and the gold standard for traditional Italian pasta and pizza sauces.
As you pick up the cans of these two varieties of tomatoes, read through the labels, and compare the price tags, it’s only natural to wonder about the difference between them—and what that means for how you stock your pantry and what ingredients you prepare your food with.
As usual, we at Home Cook World have got you covered. Read on below to find out.
The Difference Between Roma and San Marzano Tomatoes
Both Roma and San Marzano tomatoes are plum tomato varieties commonly used for canning. This, however, is where the similarities between the two end and the differences begin.
Roma tomatoes are the everyday tomatoes. They are economical, widely available, and have this deep, concentrated flavor that makes them ideal for both canning and cooking down. All in all, great tomatoes for casual dinner for you and the family Monday through Friday.
San Marzano tomatoes are the splurge tomatoes. You know, the kind you buy when you and wifey or hubby want to make pasta pasta—with Italy-imported spaghetti and Parmigiano Reggiano DOP grated on top—the kids with grandpa and grandma and the table set for a romantic dinner.
What Are Roma Tomatoes?
Roma tomatoes (Solanum lycopersicum) are a variety of plum tomato developed by American scientist William Porte.
Roma tomatoes are the first choice for canning and for making sauces, soups, and stews. They are less juicy than tomato varieties for slicing, and have thick walls and a dense, dry flesh that holds its shape well during canning and cooks down gracefully.
Roma tomatoes were invented in the 1950s by the Agricultural Research Service of the USDA. They are a cross between the San Marzano and Red Top varieties that is resistant to wilt and pests and grows in all climates.
When fully ripe, Roma tomatoes have the shape of a pear or elongated egg and a yellow to bright red color. A determinate variety of tomatoes, their fruits ripen once and are harvested in summer.
How to Shop for Roma Tomatoes
Canned Roma tomatoes are a highly versatile tomato variety. They’re sold whole peeled, diced, and crushed, and they’re also available as tomato sauce and its more concentrated alternative, tomato paste.
From a can of whole peeled tomatoes, you can make anything from crushed tomatoes to tomato paste with your hands, a knife, or a food processor. Diced and crushed tomatoes are convenient, but they also contain additives that help them keep their shape, so they don’t cook down.
Generally, canned tomatoes with basil are more aromatic and have a richer flavor than those without basil. Sometimes this is welcome, and sometimes it’s a bit too much; when in doubt, stick to the type of tomato listed in the recipe.
At the store, read the labels carefully and pick up cans from reputable canners, preferably with less sodium and as few additives as possible.
What Are San Marzano Tomatoes?
San Marzano tomatoes (Solanum lycopersicum) are a variety of plum tomato originally grown in the volcanic, nutrient-rich soil of San Marzano sul Sarno, a small town near Naples, Italy.
Thanks to their rich flavor that strikes the right balance between savoriness, sweetness, and acidity and their dense, meaty interior with fewer seeds, San Marzano tomatoes are considered by many to be the best sauce tomato in the world.
San Marzano tomatoes are one of the three tomato varieties officially allowed to be used for the preparation of the genuine Neapolitan pizza (Verace Pizza Napoletana), and a tomato of legendary quality most praised by Italian and international chefs.
As Nicholas Blechman explains for The New York Times, they are grown in small plots of farmland in the Agro Sarnese-Nocerino region of Italy’s province of Salerno, right below Mount Vesuvius. Every year, they are grown under regulated conditions and hand-harvested by an old-school generation of Italian farmers.
How to Shop for San Marzano Tomatoes
If you live in a European Union member state, simply look for San Marzano tomatoes in the grocery store. Legally, only tomatoes grown in Italy that meet the strict regulations of the San Marzano Tomatoes Consortium can be labeled as such.
If you live in the United States, keep in mind that not all canned tomatoes labeled San Marzano are grown in Italy. Look for the D.O.P. seal and the words Pomodoro S. Marzano dell’Agro Sarnese-Nocerino (a tongue twister, I know) on the label.
D.O.P., short for Denominazione d’Origine Protetta or “Protected Designation of Origin,” is a certification seal that guarantees the origin and quality of Italian products. It tells you that the tomatoes in the can are of Italian origin.
San Marzano D.O.P. tomatoes are always canned whole—never diced or crushed.
Rich and meaty, canned Roma tomatoes are the must-have type of tomatoes to keep in the pantry. They’re great for daily cooking and yield the most delicious sauces, soups, stews, and bakes.
But if you want a taste of Italy, reach for San Marzano D.O.P. tomatoes. These tomatoes from the fertile and nutrient-rich soils of Mount Vesuvius are legendary for their aroma and flavor, and they’re worth spending a little extra for that special occasion.