How Are Heirloom Tomatoes Different From Regular Tomatoes?

"Normally, heirloom refers to a variety of tomato that has some nostalgia attached to it or some cultural reference," says Joseph M. Kemble, a retired extension vegetable specialist and professor at Auburn University in Alabama. Like a family Bible, antique desk or old timepiece that's handed down from generation to generation, heirloom tomatoes are passed down from season to season.

Some varieties can be traced back for centuries. Take, for example, the Brandywine tomato. "It's been around since the 1700s, probably brought here by the early settlers," Kemble says. "Or, like many of my Italian relatives, they brought tomatoes here and have grown the same variety for 60 to 70 years."

What qualifies a tomato as an heirloom, according to the Farmers' Almanac, is that the seed is from a single genetic line that has remained "bred true" for at least 40 to 50 years. Although, Kemble points out, a few hybrids and younger varieties sometimes get lumped into the heirloom tomato category. And that's OK.

There's no heirloom tomato certification or "tomato police" overseeing the authenticity of the varieties that claim to be heirlooms. And really, confirming a tomato's lineage can get a bit weedy even among gardeners with the best intentions. Heirloom tomatoes are open-pollinated, meaning they are pollinated naturally by birds, insects, wind or human hands. If two or more varieties are planted too close to each other, Mother Nature may play a role in cross-pollinating and creating a mysterious new variety.

In an effort to better define what constitutes an heirloom tomato, tomato experts Craig LeHoullier and Carolyn Male introduced four categories:

Once upon a time, people would stroll down to their local market and buy locally grown tomatoes which, by definition, were likely heirloom tomatoes, though not called such, says Hab Setze of Habersham Farms, atop Lookout Mountain in Mentone, Alabama. "Up until World War II, no one was shipping fresh produce across the country." For one, the tomatoes were delicate creatures — highly perishable, prone to disease and they simply didn't travel well.

Then farmers started tinkering with the plants. Those hardy, perfectly round and perfectly red tomatoes you find stacked in the produce section of the grocery store are hybrids bred for traits such as high yield, disease resistance and the ability to ship and store well. Not only are they pleasing to the eye, but due to their high yield, they're also easy on the wallet.

Comparatively, "when you produce heirlooms at scale you get a lot less yield per amount of land that you're farming," Setze says. "So, you have to sell them for a lot more."

Unfortunately, creating an iconic round, red, affordable tomato that's also hardy and disease resistant means you lose other desirable traits — like flavor.

"It doesn't matter what you do to them. You can baby them. You can talk nice to them. You can let them sit there on the vine and get ripe. And they're still bad," Kemble says. There are exceptions, of course. One is the Celebrity, a commercial hybrid that is so tasty it is sometimes mistaken for an heirloom, he says.

But don't be fooled by the hype. Not all heirlooms are tasty. "There are some heirlooms I've had that, frankly, are terrible," he says, adding that taste is subjective. What one finds wonderful, another may find unpalatable. "I remember an heirloom I tried from the Czech Republic. It was really interesting. It had sort of a Pine-Sol flavor. But, boy, that person who grew it loved it and I was thinking, 'This is really awful.'"

For all intents and purposes, heirloom tomatoes can usually be identified by their appearance. "It's their uniqueness. They just look interesting," Kemble says.

Heirloom tomatoes come in a variety of shades, from Granny Smith apple green, sunshine yellow and vibrant orange to a pleasing pink and a rich purple-brown. They also come in a range of sizes and shapes and are often scarred with deep grooves — "some say ugly," Kemble adds. But intriguing, nonetheless.

"There's absolutely something unique about them," Kemble says. "Something interesting — a taste or a look. Something that tends to harken back to our childhood."