Roma Vs Plum Tomatoes: What's The Difference?

Growing up with a British mother, there were always jokes between the pronunciation of tomAtoes versus to tomAHtoes. In the end, it matters little how you say the word — but a lot whether you know the difference between specific tomato varieties. That includes ones with very similar characteristics, such as Roma and plum tomatoes. They generally share a deep-red coloration and oval rather than round appearance. But things become much more nuanced when realizing one important thing: one is a tomato "category," and the other is a "variety" within that category. 

Plum tomatoes are a relatively broad category of tomatoes that includes several varieties — and Romas happen to be one of those. In other words, all Romas are plum tomatoes, but not all plums are Romas. Many family members reside within the plum clan, including popular varieties such as Amish Paste, Big Mama, and the well-known San Marzano from Italy. From that perspective, it's difficult to directly compare Romas and plums. The question instead shifts to the differences between Romas and other types of plum tomatoes.

Before comparing Roma tomatoes with another plum tomato variety, it helps to recognize what most plum siblings have in common. They generally harbor fewer seeds and less juice than larger round tomatoes. That makes plum tomatoes, including Romas, ideal for specific culinary applications. Sauces thrive with the "meaty" texture and stability of plum varieties, which cook down into rich, thick, ladle-worthy toppings for pasta, pizzas, and sandwiches. Salads benefit for similar reasons: They hold firm, avoiding soggy salad messes. And most are excellent choices for canning. 

But tomato varieties within the plum category do have differences, so here's a brief look at two of them: San Marzanos and Romas. San Marzanos are considered royalty in the plum-tomato kingdom. Genuine Italian San Marzanos grow only in Sarnase Noccerino, an especially sunny area in Italy's Campania region. Volcanic soils, specific water tables, and its own microclimate produce these luscious plum tomatoes. They have longer, thinner shapes than Romas and bear certain mineral concentrations, bringing a delicate balance of tangy and sweet flavors.

Romas, on the other hand, are a newer variety of plum tomato, developed in 1955 by the USDA's Agricultural Research Service. If it feels like an American version of San Marzano tomatoes, that's because ARS scientists bred Romas from San Marzanos and Red Tops, intentionally creating a hardy-fleshed, pest-resistant tomato to thrive in varied climates. That heartiness also creates the standout qualities for thick Roma or Baby Roma tomato sauces without the higher price of San Marzano tomatoes.