Paste tomatoes are a distinct category of tomato cultivar prized for characteristics that make them uniquely suited for cooking and preservation. Unlike the large, juicy varieties used for slicing, these tomatoes are intentionally bred for their dense, fleshy structure. This composition dictates their superior performance in the kitchen, making them the preference for cooks focused on sauces, pastes, and canned goods.
Physical Traits That Define Them
Paste tomatoes are defined by their high ratio of solid flesh to liquid juice, a characteristic often referred to as high total soluble solids (TSS). This composition is a result of their thick pericarp walls, which are the meaty outer and inner layers of the fruit. Compared to slicing tomatoes, paste tomatoes contain significantly less water, making the interior dense and firm.
The interior structure also features a reduced number of locules, or seed cavities, and minimal watery, gelatinous material surrounding the seeds. This structural feature contributes directly to the overall meatiness of the fruit. Physically, they possess an elongated, oval, or pear-like shape, often grouped under the general term “plum tomatoes.” This combination of thick walls and low moisture makes the tomato structurally robust and less prone to breaking down into a thin liquid when cooked.
Optimal Uses in the Kitchen
The unique internal structure of paste tomatoes translates into a superior product when processed. Since the fruit contains less moisture, the time required to evaporate water during cooking is reduced. This allows cooks to achieve a thick, concentrated sauce or paste faster than when using water-heavy slicing tomatoes.
The high solids content results in a final product with better consistency and viscosity. This density is important for products like tomato paste, ketchup, and thick pasta sauces, where a velvety texture is desired. The thick walls and low water content also make these varieties ideal for canning, as they retain their shape when processed whole or diced. They are also excellent for drying, as their minimal moisture content allows them to dehydrate quickly into intensely flavored pieces.
Common Varieties and Growth Types
The most widely known paste tomato is the Roma, frequently found in grocery stores and used for everyday sauces and purees. The San Marzano is another highly regarded variety, distinguished by its thin skin, low acidity, and sweet flavor, making it a favorite for authentic Italian sauces. Other popular types include the Amish Paste and the Speckled Roman.
Gardeners choose paste tomatoes based on their growth habit, classified as either determinate or indeterminate. Determinate varieties grow to a fixed, bushy size and produce most of their fruit in a concentrated period of a few weeks. This concentrated yield is ideal for bulk processing, such as a single large canning session. Indeterminate paste varieties grow as vines and continue to produce fruit steadily throughout the season until the first frost, providing a continuous, smaller harvest suitable for fresh sauce-making.