"Food with integrity," but for how long? (Photographer: Patrick T. Fallon/Bloomberg)

Chipotle said yesterday that it has stopped serving pork at a third of its restaurants, or some 600 establishments countrywide, citing a standards violation by one of its suppliers. It marks the first time the burrito slinger has been forced to pull a topping from its menu. But if Chipotle continues to expand as it has in recent years, it's hard to imagine this is the last time the restaurant chain will face a problem like this.

The reason Chipotle has been forced to pull carnitas from so many of its menus is that one of its pork suppliers—likely a very large pork supplier, given how vast the impact has been—wasn't treating its pigs in a way that met the company's standards. Chipotle hasn't said that explicitly, but Chris Arnold, the company's communications director, admitted as much to me.

"This is fundamentally an animal welfare decision and it's rooted in our unwillingness to compromise our standards where animal welfare is concerned," he said.

Chipotle only learned of the standards breach while auditing the supplier's operations during a routine check-in. It's not clear how long Chipotle was serving meat from a supplier whose practices it doesn't condone, nor how long it will be before Chipotle is able to replace that supply.

Chipotle's core mission, selling "food with integrity," centers around what the company calls a respect for all participants in the supply chain, including animals, farmers and the environment. Ever since the company first opened more than 20 years ago, it has worked to make good on that promise by seeking out ways to cut its carbon footprint, carefully choose its farmers, source its ingredients locally where it can, and work with meat farmers like Niman Ranch Pork Company, which has long been a leader in humane animal practices.

This has been a major key to the chain's success and why it's beating so many of its competitors. While fast food giants, like McDonald's, have struggled after years of prioritizing cheapness in its supply chain, Chipotle has thrived by putting sustainability first. The unparalleled success of the chain is glaring proof that people are willing to pay a bit more for that promise. Chipotle's growth speaks for itself — there are, as I have noted before, few things you can count on more than Chipotle's ability to sell more and more burritos.


Nowhere to go, but up.

But the company's success has also been a lesson in how hard it is to scale the entirety of a business like Chipotle, with its promise to sell "food with integrity."

In 2013, the company was forced to begin serving "conventionally raised beef," after it became clear that there was no longer enough antibiotic and hormone free beef to go around. "We just need more (and it isn't there)," Arnold lamented to Businessweek at the time. The reason Chipotle is willing to serve conventionally raised beef and not conventionally raised pork is that the latter, according to Arnold, compromises animal welfare in a way the former doesn't.

"Given these stark differences, serving pork from conventionally raised pigs is not an option to us," he said. "We would rather not serve pork at all, than serve pork from animals that are raised in this way."

That's a laudable stance from an animal rights perspective. Pulling pork from almost 600 restaurants indefinitely is almost certain to cost Chipotle a lot of money. And it's exactly the sort of decision Chipotle might not be able to keep making not if if it wants to serve more burritos to more people, and still include pork as an ingredient.

As Paul Shapiro, vice president of farm animal protection for The Humane Society of the United States, told the Associated Press on Tuesday, farms that raise pigs outside of gestation crates still represent a "very small portion of the pork industry." Meanwhile, Chipotle wants to capture a very large portion of the American fast food industry. Those two realities could eventually prove untenable, because at the moment, they simply don't add up.

The Washington area has seen a boom in fast casual dining restaurants using a Chipotle-like model of building your own meal starting with a base, adding a protein and vegetables, and topping it with garnishes and sauces. The Chipotle-owned ShopHouse and D.C.-based Cava Grill are two newer outlets where customers can build a bowl. (Jayne W. Orenstein and Pamela Kirkland/The Washington Post)