Mission Pie, the 12-year-old restaurant and bakery at Mission and 25th, deploys the clever slogan, “Eat Pie. Live Forever.”

If only.

And, alas, no one would think to offer such claims about making pie — or running a business in San Francisco.

The establishment’s co-owners, Krystin Rubin and Karen Heisler, have confirmed to Mission Local what they’d earlier disclosed to staff and some loyal customers — they are pulling the plug on their long-running joint venture come Sept. 1.

“As a business founded with some very clear values, we have reached the point where Mission Pie is not going to be economically viable into the future unless we make serious changes,” explains Hiesler. “And we’ve spent two years evaluating our options and we haven’t found anything that doesn’t either compromise our values or look like a bad business proposition.”

The purpose of Mission Pie was never as simple as making pies, selling pies, and Step 3: Profit. Rather, the goal here was to produce high-quality food from high-quality, ethically sourced ingredients, price it at a level people in the neighborhood could ostensibly afford, and treat the staff well.

There are currently 25 employees. They earn between $15.75 and $20 an hour, with tips perhaps adding $7 to that. They have health insurance. They have sick leave and paid vacations. They have a 401K with an employer match. They are paid a transit subsidy.

And there’s the rub: “We got to a point a couple of years ago that the increases in wages were still not good enough,” says Rubin. “People just couldn’t live on what Mission Pie was able to pay, even at our most ambitious.”

And, rather than compromise their principles, Rubin and Heisler have opted to scuttle the ship.

“It is possible to launch a beautiful enterprise in this time and place,” Heisler says. “But this time and place is no longer a match for this particular enterprise, with its particular goals and ambitions and values and priorities.”

The decision to shutter Mission Pie was not a cavalier one. Rubin and Heisler — a married couple — explored a number of possibilities. They considered delivery options such as Caviar or Postmates. But, as a recent Mission Local article explored, this turned out to be a transcendently unsuitable solution. Third-party delivery services often charge a 30 percent commission from the food producers, and Mission Pie, as is typical in the restaurant industry, has a profit margin of only six percent or less. What’s more, the gig workers delivering the food are, all but certainly, involved in an exploitative labor situation that violates California law and leaves state taxpayers on the hook to provide their social safety net.

So, that was right out.

They looked into a mail-based business not unlike ordering New York deli from Zabar’s. But that wouldn’t work either: Mission Pie’s products, Rubin notes, “are intended to be eaten in one or two days. We use fresh fruits. We use very little sugar and no stabilizers or preservatives.” Plus, the environmental side effects of mailing items across the country is unappealing.

So that wouldn’t work either.

Neither would pushing their products into local grocery stores. The freshness issue complicates everything and means Mission Pie certainly couldn’t participate in a buy-back of unsold goods.

Could Mission Pie move to cheaper environs? Rubin and Heisler note that they’ve been participating in the Grand Lake farmer’s market across the bay and running into a significant number of priced-out erstwhile Mission residents. But restarting in Oakland would, in Rubin’s estimation, run between $200,000 to $500,000 — and be antithetical to a business that is, after all, called “Mission Pie.”

“We opened and grew and ran a business very much based on being right here — this location,” says Rubin. “It was a gathering place. And our kitchen here is very big. The intention was designing a good workplace. We don’t have the maximum number of tables and chairs. We seat below legal capacity.”

Despite spending more, by design, on ingredients and staff, Rubin and Heisler claim their profit margin was on par with industry standards due to a near-fanatical devotion to running a waste-free kitchen. Rubin will only buy in-season ingredients: “We’re not tied to having certain things on the menu all the time.” They even installed solar panels on the roof to knock 25 percent off the electric bill.

Even still, it wasn’t sustainable. In recent months it became clear to Mission Pie’s founders that running their business in a manner that adhered to its founding principles in today’s San Francisco was a retail version of the Kobayashi Maru. It was a no-win scenario in which the best possible option was to concede in a dignified manner.

They do so with a bittersweet feeling toward this city — and Heisler is a third-generation San Franciscan. It’s quite the thing to make equitable treatment of your employees a founding principle of your business, and fall short, even while paying as beneficently as possible — all while watching Twitter et al. being handed a payroll tax break.

Heisler owns the building housing Mission Pie, which she bought years ago in order to bring this restaurant into being. She and Rubin live in one of its six residential units. She may rent out the ground-floor retail space. She may sell the whole building. It’s all up in the air. So much is.

“We look forward to not working in the same place as each other,” said Heisler, inducing a grin from Rubin. “That will be a novelty.”

Mission Pie’s 13th-annual community pie contest will be held on-site on Aug. 17. This will, barring unforeseen lunacy, be the last such event.

And, two weeks later, the ovens go cold.

Pie on a Mission from Mission Local on Vimeo.