How Do Heirloom Tomatoes Get Their Unique Shape?

In a supermarket full of uniformity, the variety of heirloom tomato shapes really stands out. Piled next to lines and lines of identical Roma and Beefsteak tomatoes, the colors and lumps of heirlooms give way to a host of questions. What exactly is an heirloom tomato anyway? Do they taste better? Or are those misshapen tomatoes just another form of visual produce marketing? The answer to that last question is "kind of," but in the best way possible. Ultimately, heirloom tomatoes' unique shapes and colors are their natural form because they were passed over for genetic modification.

The real question you should be asking when thinking about heirloom tomatoes isn't why they look so different; it's why all the other types of tomatoes look the same. In nature, fruits and vegetables don't have the perfectly identical shapes you see on grocery store shelves. All tomatoes you eat have been bred and had their DNA altered in some way, either through genetic engineering or through natural processes like hybridization and domestication. Traditionally, this was done through cross-pollination, where two different species of plants are combined, or through farmers selecting seeds from plants with characteristics they considered ideal, gradually changing the forms of certain domestic crops over generations. This started changing in the 70s, as the advent of genetic engineering allowed scientists to start making those changes more targeted and less naturally random. But the uniformity of tomato shapes actually started before that, and had more to do with modern consumer markets than anything.

The age of identical tomatoes started after World War II. It was during this time that major breakthroughs in technologies like refrigeration and transportation kicked off the growth of industrial agriculture. Previously, fresh tomatoes had mostly been available within a small range of where they were grown, but now they could be shipped nationwide to people nowhere near a tomato farm. However, even with modern technology, shipping tomatoes presents issues, as they bruise easily. Marketers have also noticed that consumers prefer perfectly red tomatoes. But to achieve that color, tomatoes needed to be picked before they were ripe, and the rate they turned red after picking was not consistent.

So, even before creating GMO foods, producers got to work and started selecting tomatoes and breeding hybrids that had thicker, tougher skin to better survive shipping. They were also bred for uniform color, shape, and size, which also helps in shipping and is seen as more appealing to shoppers. The problem is that in this process, the flavor was totally neglected. What makes tomatoes ship well and look good doesn't necessarily taste good. And people noticed the tomatoes they were buying started tasting bland and watery. To remedy this, some people started growing and looking to buy "heirloom" varieties of tomatoes, which were bred before the modern age of nationwide shipping kicked off in the 50s and sapped the fruit of its flavor.

Because better-tasting heirloom tomatoes come from seeds that predate most industrial agriculture, they have not been bred for visual uniformity either, hence the variations in shapes, even within the same breed. On top of that, heirloom tomato seeds were produced by farmers and backyard growers all around the world, so there are thousands of different varieties, which is also responsible for their wide variety in color and appearance.

Then there is how heirloom tomatoes are grown. They should be open-pollinated, which means done through natural wild pollination processes via bees, birds, and the weather. Being less controlled than industrial methods, open-pollinated tomatoes have a larger variety in their gene pool, which means less uniformity in color, shape, and ripening.

However, uniquely shaped heirloom tomatoes do not guarantee a great taste or a more natural origin, even though it's a good sign. The term heirloom, like "natural," is not very regulated, and producers can create hybrid tomatoes that look like heirlooms without actually being the real deal. Heirloom tomatoes can also be produced at an industrial scale and shipped across the country when tomatoes are out of season, like any other variety, falling prey to the same mealy blandness. So, unless you are getting heirloom tomatoes from a local producer you trust, the only way you can know for sure is to actually taste them too.