When making a pasta sauce from scratch, you'll probably have to decide between San Marzano and Roma tomatoes, the two most popular types of Italian tomatoes for authentic sauces and other recipes. You may wonder what the difference is between these two varieties, and which one is better for which purposes.

The elongated Roma tomatoes are believed to be a hybrid of the famous San Marzano tomatoes and Pan American tomatoes. Their flesh is more dense and meaty than juicy, with high sugar and acid levels and a low moisture content, making them great for salsas, bruschetta, tomato soup, and quick sauces.

San Marzano tomatoes, which can only be grown in the fertile volcanic soil of the Agro Sarnese-Nocerino region of Italy, are longer than Roma tomatoes, with a mild acidity. These sweeter and jammier tomatoes are generally considered the best variety for tomato sauces, but that doesn't mean Romas are always inferior.

While all these differences do stand, Romas and San Marzanos are quite similar overall, as both have a higher flesh-to-juice ratio and fall into the category of plum tomatoes. In essence, San Marzano tomatoes are the fancy, artisanal choice for those who can find them, while Roma tomatoes are a good, affordable alternative.