How To Tell If Your San Marzano Tomatoes Are The Real Deal

San Marzano tomatoes are considered one of the best tomatoes in the world for sauce, according to Martha Stewart. The tomatoes are plum tomatoes, a long finger-shaped type that is used to make sauces, tomato paste, and tomato puree because the flesh is thicker and there are fewer seeds and less seed jelly. The famed tomatoes from Italy are sweet with the right amount of acidity and a rich tomato flavor.

Many foods that are produced in Italy are tightly regulated, such as Parmigiano-Reggiano cheese. The government designates areas in the country and producers who can make these foods with "DOP" or Denominazione d' Origine Protetta label, which is Italian for Protected Designation of Origin. These regulations specify the type of tomato that can be grown, how they are grown, where they are grown, their physical appearance when they are picked, and even that they must be harvested by hand and not a machine.

Sounds like these tomatoes would be perfect for your special lasagna, right? The problem is, you may not be buying real San Marzano tomatoes, even if they are expensive, per Food & Wine. Here's how to tell if your San Marzano tomatoes are the real deal.

Real San Marzano tomatoes are grown in the Agro Sarnese Nocerino region of Italy, according to Pastene. This is between the cities of Naples and Salerno, where the climate is perfect for growing these red beauties — and they aren't cheap. While a can of ordinary tomatoes costs about $2 on Amazon, real San Marzano tomatoes run between $6 to $7 a can.

So, if you are paying that kind of money, you want the real thing. Unfortunately, Alton Brown says that about 95% of the tomatoes sold in the United States labeled San Marzano are fake. 

The problem is that in the U.S., while there are many laws about what can and can't be put on food labels, the Denominazione d' Origine Protetta is not regulated, Danielle Aquino Roitmayr told Taste. A company can import tomatoes that are not necessarily San Marzano, slap a DOP designation on the can, and no one is the wiser — except you, because you are about to learn the key details about the real thing.

There are a few ways you can tell you have the real, honest to Pete, true San Marzano tomatoes in your hot little hand. First, these tomatoes are always sold peeled and canned. They are never chopped, diced, or pureed, per Life Hacker, but are packed whole or in fillets. Any tomato that is diced or smushed up in any way that is claiming to be San Marzano is a fake.

Then, there are things to look for on the can. The DOP seal will be there, of course, but there should also be a Consorzio San Marzano certification number stamped on the bottom of the can. The label may also add where the tomatoes were grown. If they were grown in the U.S., they are not true San Marzano tomatoes.

If you do happen to buy real San Marzano canned tomatoes and want to make your spaghetti sauce or lasagna with them, try these recipes: classic lasagna, baked spaghetti, or fidelanza.