A History of the Tomatillo

The Tomatillo has a history far older than the red tomato we’re all used to. In 2017, a study published in the journal Science by Peter Wilf and his team detailed the discovery of a fossilised tomatillo in Patagonia, Argentina. This fossil, belonging to the Physalis genus, dates back roughly 52 million years. It’s a bit of a game-changer for botanists because it suggests the nightshade family evolved in Gondwana—the ancient supercontinent—long before the continents drifted into their current positions. While the plant eventually moved north, its biological "blueprint" was already millions of years old by the time humans first encountered it!

Their domestication took place in Mesoamerica, likely starting with the Olmecs around 1000 BC. Archaeologist C. Earle Smith noted in his 1967 research on the Tehuacán Valley, that the seeds appear in the archaeological record as early as 900 BC. Proving they were a reliable food source well before the rise of the great empires. In the highlands of Guatemala, the Maya used the Tomatillo as their primary "citrus", before the Spanish brought lemons and limes from Asia. The tart fruits provided the essential acidity needed to balance a diet of maize and fatty meats. By the time the Maya were at their peak, the tomatillo had been intergrated into a complex agricultural system called the milpa. You might have heard of the "Three Sisters"—maize, beans, and squash—but in many regions, the Tomatillo was the "Fourth Sister." It wasn't always formally planted; instead, it was an "encouraged weed" that grew in the shade of the maize stalks. Unlike tomatoes, these plants are self-incompatible. A single plant cannot pollinate itself; it must have a neighbour and a healthy bee population to produce fruit. This made it a symbol of communal growth—you cannot thrive alone

Ancient Mesoamericans were master chemists, utilising every part of the plant. Traditional cooks boil the husks to make a tea for their masa (dough), the husks contain saponins and alkaline properties that act as a natural leavening agent, making tamales light and fluffy. Healers used them in limpias (spiritual cleansings) to "draw out" fever or inflammation, or to treat ear ache and respiratory issues. Modern medicine recognises they are rich in withanolides, natural steroid-like compounds.

By the time the Aztecs rose to power in the 1300s, the Tomatillo was the "default" tomato. In Nahuatl, the word for the husked fruit was simply tomatl. The red, round fruit we call a tomato today was called xitomatl ("plump tomato with a navel"). When the Spanish arrived in the 1500s, they simplified both to "tomato." Because the red version adapted better to Mediterranean climates, it took the name and ran with it, leaving the "Tomatillo" (literally "little tomato") to be viewed as a niche specialty by the rest of the world.

When the Spanish first arrived in the Aztec capital of Tenochtitlán in 1519, they encountered a marketplace at Tlatelolco that was far more sophisticated than anything they had seen in Europe. Bernal Díaz del Castillo, a soldier in Hernán Cortés’s army, wrote in his memoirs, The True History of the Conquest of New Spain, about the overwhelming variety of produce on sale. The reaction in Europe was somewhat lukewarm compared to the reception of the red tomato. Seeds were brought back to Spain and Italy in the mid-16th century, where the plant was first described in botanical literature. One of the earliest European mentions comes from the Italian physician and botanist Pietro Andrea Mattioli in 1544. He categorised them alongside other nightshades, but they were largely treated as botanical curiosities rather than a new food staple.

When it comes to the most iconic tomatillo recipe, there is no contest: it is Salsa Verde. While there are dozens of regional variations, the "gold standard" version is arguably Salsa Verde Tatemada (roasted green salsa). This recipe is considered iconic because it utilizes the ancient technique of dry-roasting ingredients on a comal (a flat clay or cast-iron griddle). Roasting the tomatillos, onions, garlic, and chillies until the skins are charred and blistered transforms the fruit’s sharp, citrusy acidity into something deeper and slightly smoky. This specific method is cited by culinary historians like Diana Kennedy as the essential link between ancient Mesoamerican cooking and modern Mexican cuisine. Once roasted, the ingredients are traditionally ground in a molcajete—a mortar and pestle made from volcanic rock. This method doesn't just puree the ingredients; it bruises the fibres and releases essential oils, creating a texture and depth of flavour that a modern blender simply can't replicate. It is this specific combination of tartness from the tomatillo and the slow-burn heat of the chilli that has remained the most popular way to eat the fruit for over three millennia.