Burritos inspire an awful lot of feelings for something that is, by design, not that special.

"The idea of a flatbread with things inside it as a way of preserving leftovers or carrying food to work or whatever; it’s not exactly rocket science, I’ll put it that way," says Jeffrey Pilcher, a food historian at the University of Toronto–Scarborough and author of Planet Taco: A Global History of Mexican Food. From its 19th-century inception in Northern Mexico, the flour tortilla and its bundled contents have been essentially utilitarian, a caloric torpedo streamlined for density and convenience. It’s an unlikely candidate for a cult object.

Dive into the minutiae that separate one carb-swaddled delivery device from another, however, and you’ll find plenty of energetic nit-picking. To many Americans, the burrito is synonymous with the glutinous, customizable offerings of national mega-chain Chipotle, which originated in Colorado but is nominally inspired by the burritos from San Francisco’s Mission District. To residents of the burrito’s ancestral homelands in the American Southwest, the burrito can be many things. Exactly which depends on who you ask.

To me, for example, a true burrito has french fries in it.

That definition pinpoints me as a child of an approximately 30-mile stretch of California’s far-southern coast. My hometown of San Diego isn’t particularly well known for its culinary bona fides. But thanks to the Mexican border, there is one thing the city reliably does well: Mexican American food. San Diego’s contribution to the field is undeniable, even though it boils down to two items: the fried fish taco, imported more or less intact from Baja California, and the french-fry-laden burrito, a gloriously American invention with a fittingly arrogant name. (To call it "inauthentic" would imply it’s attempting to represent anything but the proudly excessive tastes of a single region.) Despite its limited prevalence, largely restricted to the third-largest metropolitan area of a sprawling, diverse state, San Diego’s carbohydrate bomb of choice dares to call itself the California burrito.

Over the last decade, one specific kind of burrito — a fast-casual take on a San Francisco specialty — has risen to prominence as one of the most influential fast food items in America. The rest, including my beloved California, have stayed stubbornly regional, resistant to the mainstreaming that’s amplified other strains of American Mexican food. That split is a happy accident that’s kept the California the rarest of things in the 21st century: truly local.

Tracking down the California burrito’s precise inventor or its birthdate is difficult; you can’t patent throwing a fistful of crispy potatoes into a tortilla. To trace the California’s beginnings, it helps to rewind to the beginnings of the burrito itself.

Only flour tortillas have the gluten-induced fungibility to stretch and fold without disintegrating. So the burrito came to be in Mexico’s Northern regions, like the state of Sonora, where flour tortillas are prevalent relative to corn ones. That’s where they stayed — at least within Mexico. "That’s the reason why the burrito never spread the way that, say, tacos did across Mexico," explains Gustavo Arellano, author of Taco USA: How Mexican Food Conquered America and editor and publisher of OC Weekly. "Because there are no flour tortillas [outside of certain regions]. On the other hand, in the United States, the reason burritos took off the way they did is because flour tortillas were far more prevalent. … Flour tortillas have outsold corn tortillas [in the U.S.] for forever."

The first documented occurrence of the burrito in the United States comes from a New Mexican cookbook from the 1930s. Mass consumption initially occurred in the workplace, not the home, as American farmers looked for a way to quickly and inexpensively feed Mexican guest laborers employed under the Bracero program in the 1940s. "The farmers who were contracting these Mexican men figured, ‘Oh yeah, a meal of flour tortillas where you just put beans and rice in them?’ It’s cheap to make, it’s easy to make, and hey, it’s Mexican food, so let’s feed these workers with them," Arellano says. "But a lot of these workers were coming from central Mexico. They had never heard of a burrito before. … A lot of them hated these burritos." Again, not exactly the stuff of impassioned evangelism.

Regional variation began with the so-called Chicano burrito: beans and cheese ensconced in a waxier style of tortilla, available at Los Angeles establishments like Al & Bea’s. National dissemination started after World War II; the first Taco Bell, which opened in the L.A. suburb of Downey in 1962, had burritos on the menu. So did the inaugural Del Taco in rural San Bernardino County two years later. At the same time, an equally significant burrito development was occurring several hundred miles to the north, though its national impact wouldn’t be felt for decades.

The right to call oneself the creator of the Mission burrito is hotly contested. Raul and Michaela Duran of the San Francisco district’s Taqueria La Cumbre claim they came up with the idea on September 29, 1969; El Faro’s Febronio Ontiveros said he christened the concept a full eight years earlier, on September 26, 1961, while serving a crew of ravenous firefighters. What isn’t up for debate is the neighborhood-specific tradition that came out of the ’60s: rice, beans, meat, vegetables, and condiments in a foil-wrapped tortilla, more varied and maximalist than the humble Chicano style and enough to fuel anyone through not just a shift, but an entire day. (Though for what it’s worth, Arellano favors El Faro’s story over La Cumbre’s.)

The Mission burrito became one of the first hyperlocal burrito styles. The historically Mexican American Mission District occupies less than two square miles of land, with a population of fewer than 50,000. Yet the results of this concentrated set of laboratories was deemed worthy of the wide-eyed evangelism treatment, most famously by a former line cook at 1980s San Francisco power restaurant Stars named Steve Ells, who opened the first Chipotle in Denver in 1993, a thousand miles away from his former stomping grounds. He’s not the only major exporter, though; when I speak to brothers Leo and Oliver Kremer, who opened their first Dos Toros Taqueria near New York’s Union Square in 2009, there’s a familiar enthusiasm to their tone.

"A lot of pent-up emotions came out of people" when Dos Toros first started catering to fellow West Coast ex-pats, Leo says, which sounds ridiculous until considering what it’s like for someone to start selling an edible solution to homesickness. But it takes more than commercialized nostalgia to launch a profitable business. Dos Toros currently boasts 12 locations with a 13th opening in March, and after an infusion of investment capital last year, the company plans to expand to other cities like Chicago. That volume, of course, pales in comparison with Chipotle’s thousands of locations. But both the Kremers and Arellano speculate that the Mission burrito’s success has as much to do with process and savvy marketing as the food. "[Chipotle] is credited with the assembly line" style of ordering, Leo points out. Ells "knew how to market food," Arellano says. "He also knew where to open up Chipotles. He started opening them up in college towns across the United States. College kids, they want drunk food" — and cheap, portable food. Chipotle established the Mission burrito’s ability to check all three boxes in the popular consciousness, opening the door for newer chains like Dos Toros to essentially piggyback off its name recognition while also offering an improvement. In Dos Toros’ case, that meant offering a burrito that hewed closer to the Bay Area source.

But the Mission burrito isn’t the only one to satisfy all those requirements. "French fries in a burrito?" Arellano marvels. "That’s the ultimate college food." And yet the California burrito remains a footnote while the Mission burrito has shed its qualifier. To most Chipotle customers, the contentious Mission staple is just a burrito.

By all accounts, the California burrito is a recent invention, even by the standards of a food that’s been widely consumed in the United States for just 70 years. San Diego is full of cheap, 24-hour or at least late-night taco shops, most of which serve simple, affordable burritos filled with meat, condiments (cheese, sour cream, salsa, maybe guacamole), and little else — the opposite, in other words, of the Mission burrito and its compression of the entire food pyramid into a single bite. Mexican immigrant Roberto Robledo opened his inaugural Roberto’s Taco Shop in 1964, founding the first of dozens of regional solo stands and mini-chains with ’berto’s in their title. Robledo employed cousins and friends brought in from his village in Mexico, and as they went on to create their own small businesses, they barely tweaked the name: Gilberto’s, Rigoberto’s, and Alberto’s are all established presences on the San Diego scene.

In lieu of rice and/or beans, french fries were introduced sometime in the 1980s, likely at Roberto’s. Local chain Santana’s also lays its claim (Disclosure: I went to elementary school with the founder’s kids, so I’m biased, but ultimately trust Arellano’s research). The name, too, is something of a mystery; the first documented instance of a "California burrito" as a listed menu item Arellano found in his research was actually at an ill-fated Mexican spinoff of Carl’s Jr., and though a burger restaurant would be a logical place for the California’s Frankenstein-like hybrid to emerge from, fries weren’t involved.

Though its provenance remains uncertain, the California burrito quickly cemented itself as part of San Diego culture as hungry surfer bros and beach-town stoners took to the idea. Just like in the Mission District, isolation, hometown pride, and the narcissism of small differences breeds hard-core partisanship. Everyone has a preferred style and a preferred outlet. I’ve had extensive, borderline-philosophical conversations about whether fries should be crunchy — like at popular mini-chain Lolita’s — or soft. (It comes down to whether you believe they’re in the burrito as their own, stand-alone thing or to absorb and amplify everything else.)

My taco shop of choice is Don Carlos, a family-owned business just blocks from my high school in the affluent seaside neighborhood of La Jolla. Co-owner Ryan Hill took over the shop from his cousin in 2001, at which point California burritos were already a best-seller. Like most San Diegans, Hill has his own opinions about how things should be done: "I use a crinkle-cut fry as my fry of choice. It has a higher surface area, and that gives it a crunch. I want you, when you bite down, to actually have some of that crunchy feel — not like some of these places where they use steak-cut fries, where it’s like air, or the shoestring, which doesn’t really taste like anything." Also, you can put guacamole in your California if you want to, but that tips it over into "too wet, too sloppy" territory. As for the Mission burrito? Hill deadpans: "I wasn’t that impressed."

There have been a few attempts to transplant the California burrito outside its native habitat. New York has Lucha Lucha, a duo of taco shops that advertise "San Diego Mexican in Brooklyn." Mostly, though, the California has stayed domestic. In Los Angeles, where tacos reign supreme, I’ve hunted down and tried two subpar renditions of the California before accepting that the style has yet to migrate up the 5. (One was weirdly liquid-y; the other was about 90 percent overdone fry.)

"What’s funny to me is, nobody can get it right outside of San Diego," Hill says, an irritating status quo for enthusiasts that’s also proved something of a blessing. The California burrito’s rarity preserves something special about the act of homecoming, allowing San Diego to maintain a sense of place — even as national franchises have rendered places more indistinct than ever. Grossing out friends and colleagues when I tell them how much red meat and oil-soaked potatoes I used to eat on a regular basis is merely a bonus. It’s similar to how people from Cincinnati feel about chocolate-spiked chili, or St. Louis natives feel about toasted (read: deep-fried) ravioli. The comfort of specificity remains, a temporary holdout against the homogenizing impulses of capitalism.

Maybe that’s why the burrito still manages to get people’s hackles up. Protectiveness certainly explains the outcry that greeted FiveThirtyEight’s infamous Burrito Bracket from 2014, an effort to apply objective standards to an object people love to argue about. Los Angeles Times critic Jonathan Gold, himself a Chicano burrito proponent who once called Mission burritos "monstrous things wrapped in tinfoil," tactfully but forcefully suggested that site proprietor Nate Silver stick to sports and elections. After the bracket had run its course, the consensus on which burrito is best remained divided as ever, with just one point of agreement uniting all those fractious camps. The burrito can’t be quantified — it can only be consumed. Preferably with french fries.