A plum tomato, also known as a processing tomato or paste tomato, is a type of tomato bred for sauce and packing purposes. They are generally oval or cylindrical in shape, with significantly fewer seed compartments than standard round tomatoes (usually only two) and a generally higher solid content, making them more suitable for processing. Plum tomatoes are also sometimes favored by cooks for use during the tomato off-season, as they are generally considered more amenable to handling and are therefore available in a state closer to ripe than other supermarket tomatoes.
Varieties commonly available in markets include Roma VF and San Marzano (semi-determinate; a signature tomato of Italian cuisine[1]), though there are many other varieties, such as the short-season Ropreco Paste and the larger Amish Paste and Big Mama. Five hybrid cultivars grown in California constitute over 60% of total production of processing tomatoes. Small plum tomatoes (similar in size to cherry tomatoes) are known as grape tomatoes.