Are Roma tomatoes and plum tomatoes the same?
Before we answer our guiding question—what’s the difference between beefsteak, cherry, grape, heirloom, and plum tomatoes—we have to address another one: Why are supermarket tomatoes so bad?
There are two major categories of tomatoes: heirlooms , which we’ll cover below, and hybrids.
The tomatoes you’ll find in the grocery store all year are hybrids, which means they’ve been developed and bred for certain features. Not all hybrids are awful, but most supermarket hybrids are; they’re designed for disease resistance, firm meat, thick skin, and storage potential, rather than, say, taste. They are also removed from their plants when they are still as hard as rocks to avoid crushing on the journey to their eventual destination. Off the vine, they can’t develop the sugars, acids, and other flavor/aroma chemicals that make them actually taste good—so they’re sprayed with ethylene gas instead, which induces reddening and softening. As a consequence, the pucks are watery and cottony.
Heirloom tomatoes, on the other hand, are typically “open-pollinated,” which means the varietal comes from natural pollination (birds, insects, wind, etc.) rather than scientists. These tomatoes “breed true,” which means that if you plant one of their seeds, it will develop into a plant that produces tomatoes that resemble the parent. (Hybrids, on the other hand, will produce plants with features that vary from each of the parents; cultivars take around seven generations to stabilize.) Heirloom plants are those that have been cultivated for at least fifty years without crossbreeding. They come in a variety of colors, shapes, and sizes, including flawlessly round, rugged and bulbous, heart-shaped, yellow, green, black, pink, striped, and tie-dye. Their names are as diverse as they are: Black Krim, Mr. Stripey, Brandywine, and Cherokee Purple. These are the guys you’ll find at the farmers’ market at the peak of the season, the ones that just beg to be sliced and salted and eaten pretty much as is.
Beefsteak tomatoes, which can be either heirloom or hybrid, are notable for their size—they can weigh in at over a pound each, with a diameter of six or more inches—and their texture: They contain fewer seed holes than other species of tomatoes, resulting in a higher flesh-to-juice-to-seed ratio. There are around 350 types of beefsteaks out there and although you’ll mainly see the red ones labeled as “beefsteaks,” they can come in all colors: pink, yellow, green, white, technicolor. Brandywine, Cherokee Purple, and Black Krim heritage tomatoes, for example, are all beefsteak varieties.
Plum tomatoes, also known as Roma or paste tomatoes, are oval in form and smaller than beefsteaks. They also have a lower water content than other kinds, with nearly chewy flesh, making them ideal for sauce-making. These are the tomatoes you’ll find all around Italy, the most renowned of which is the San Marzano.
Baby tomatoes: cherry, grape, cocktail
Not to mention the baby tomatoes, cherries, grapes, and drinks. Cherry tomatoes are the small, round guys with thin skins that squirt juice everywhere when you bite into them. They’re incredibly delicious, have a high water content, and come in a variety of colors. Grape tomatoes are the oblong, grape-shaped tomatoes seen in grocery stores; they contain less water content and thicker skins than cherry tomatoes, allowing them to stay longer. Cocktail tomatoes are bigger than grape and cherry tomatoes, but still petite and tasty. They’re cultivated hydroponically and may be obtained in most supermarkets. If you’re looking for a decent specimen outside of true tomato season, these are usually your best bet.