The Label All Authentic San Marzano Canned Tomatoes Have
If a chef calls for whole canned tomatoes in their recipe, they're probably talking about San Marzanos. "Barefoot Contessa" star Ina Garten swears by them. Guy Fieri's wife has to stop him from stockpiling cans every time they shop, per Food Network.
Why do so many top cooks reach for the same type of tomato? Kitchn notes that true San Marzano tomatoes are grown in the volcanic soil near Mount Vesuvius in Italy. Because of these unique conditions, they have a sweet tanginess and a meaty, low-seed interior that makes them very flexible for a variety of traditional recipes (via Food Republic).
However, some chefs are skeptical. Alton Brown warns people about San Marzano tomatoes because the market is flooded with counterfeits trying to cash in on the San Marzano name. And he's right — the official organization Consorzio San Marzano reports that fully 95% of all cans labelled "San Marzano tomato" are not actual products of Italy, per Taste.
Luckily, there's an easy way to make sure you're getting the real thing — they'll all have one specific label in common.
Real Italian San Marzano tomatoes are legally name-protected
The term San Marzano refers to both the specific genus of tomato, and the name for the small Italian region between Naples and Salerno where they grow, per Martha Stewart. And this is not just a suggestion — it's a legal requirement.
The Italian government recognizes a denominazione d'origine protetta ("DOP"), or protected designation of origin, status for San Marzano tomatoes, according to Food Republic. This creates a legal requirement that tomatoes carrying this special symbol of authenticity are produced in a specific territory under certain growing conditions and processing characteristics. Similar name protections exist for Champagne and Prosecco versus sparkling wine.
However, here's where things get tricky. Just because a can of tomatoes says "San Marzano" doesn't guarantee they're the real thing. Another tomato varietal grown within the San Marzano region — or the proper tomato genus grown in another area — would not qualify for the legal protections, per Serious Eats. So to verify the officially name-protected tomatoes, high-quality canned tomatoes produced in Italy will likely have several informational labels. One of them — the key symbol you should look for (as Serious Eats notes) — looks like a red-and-yellow sunburst with a line drawing of a field and the words "denominazione d'origine protetta."
Next time you're in the grocery store and feeling overwhelmed by the wall of canned tomatoes, just remember that thanks to the Italian government, there's one specific label to help make sure the true San Marzano tomatoes don't get lost in the sauce.