From Aztec market stalls to the top-selling condiment in America: the raw, chopped sauce that never needed a stove.
Salsa's roots reach back to Mesoamerica long before Europeans arrived. Aztec markets in the Valley of Mexico, particularly at Tlatelolco, sold combinations of tomatoes, chillies and ground squash seeds that Nahuatl speakers called molli, the same root that later gave Spanish mole and eventually salsa. When the Franciscan friar Bernardino de Sahagun compiled the Florentine Codex between 1545 and 1590, his Aztec informants described exactly this kind of chile-and-tomato paste being sold and eaten daily, giving historians one of the earliest written records of the dish's basic form.
The tomato itself only reached the wider world after Hernan Cortes's conquest of the Aztec Empire in 1521. Spanish ships carried tomato seeds back across the Atlantic through the 1520s and 1530s, and by the mid-16th century the plant was growing in Spain and Italy, though it took Europeans generations to trust eating it raw. In Mexico, no such hesitation existed. Tomatoes, chillies, onion and lime had already been paired for centuries, and the technique of chopping them raw rather than cooking them down survived Spanish colonial rule largely unchanged.
In Mexican households, a fresh salsa made in a stone molcajete is treated as a mark of a properly stocked kitchen, distinct from the bottled salsa roja found in supermarkets. Families often keep their own version, passed down with small variations in chilli, onion ratio or amount of lime, and the sauce is expected on the table at nearly every meal rather than saved for special occasions.
The dish crossed into the United States gradually, accelerating after the 1848 Treaty of Guadalupe Hidalgo brought large parts of what had been northern Mexico, including much of present-day Texas, into US territory along with their Mexican and Tejano populations. Tex-Mex cooking developed from that community over the following century, and by the mid-20th century Mexican restaurants in Texas and California were serving fresh salsa alongside tortilla chips as a standard opener. The dish's commercial breakthrough is often dated to 1991 or 1992, when US grocery sales figures reportedly showed salsa had overtaken ketchup as the country's best-selling condiment, a statistic that has been repeated in food writing ever since, even if the exact figures behind the original headline are harder to pin down than the claim itself suggests.
Unlike a cooked salsa roja, pico de gallo style salsa relies entirely on raw ingredients and short marination rather than heat to build its flavour. Chopped tomato provides both acidity and water content, which is why draining or salting the tomatoes first is common in versions meant to sit longer without turning watery. Finely diced onion, left raw, keeps a sharp bite that a cooked onion would lose.
Lime juice does two jobs at once. Its citric acid brightens the whole mixture and, given enough contact time, gently softens the surface of the onion and garlic in much the same way citrus firms and pales fish in a ceviche, taking the raw edge off without any heat. Fresh coriander adds a grassy top note that fades within a day or two, which is part of why fresh salsa is always better made close to serving. Garlic and, where used, chopped fresh chilli round out the base, with the finished balance sitting on the acidity from the tomato and lime rather than on any cooked-down sweetness.
What gets called salsa varies enormously by region even within Mexico. Pico de gallo, sometimes called salsa fresca or salsa cruda, is the raw chopped version most familiar outside Mexico. Salsa verde, built from tomatillos rather than tomatoes, is common in central Mexico and has a sharper, more acidic character. In the Yucatan, salsas built around fiery habanero chillies reflect a completely different chilli tradition to the milder jalapeno and serrano varieties used further north.
Salsa's spread beyond Mexico and the American Southwest tracks closely with the growth of Tex-Mex chain restaurants from the 1960s onward, and with the wider Mexican food boom that took hold across the US through the 1970s and 1980s. It reached British supermarkets in a more limited, jarred form through the 1990s, part of a broader wave of interest in Tex-Mex and world food aisles during that decade, though fresh, unbottled salsa of the kind made at home remains far less commonly eaten in the UK than the jarred version most people encounter first.
Not quite. Salsa is a broad category covering any Mexican sauce, cooked or raw. Pico de gallo is specifically the raw, chunky, tomato, onion and lime version, sometimes also called salsa fresca or salsa cruda.
Chilling gives the lime juice and salt time to draw moisture out of the tomato and onion and soften their raw edges, which is what lets the separate ingredients taste like one balanced sauce rather than a chopped salad.
Because it is uncooked, fresh salsa is best eaten within two to three days, kept refrigerated. The coriander and onion both lose their sharpness after that, and the tomato starts to release more liquid.
It is a widely repeated claim from the early 1990s and does reflect a real shift in American condiment sales during that period, though the precise figures behind the original headline are less well documented than the statistic's popularity suggests.