Why This Baker Is Obsessed With Sourcing Unadulterated Spring Water For His Sourdough

The Outer Sunset has an under-the-radar bread baker who may very well be the only one in the city using exclusively spring water for his loaves. Greg Harmon, an Outer Sunset local, runs the tiny outlet Bear Flag Bakery and a number of times a month loads his car up with dozens of gallons of water from Marin, Napa, and Sonoma counties. A regular at the Outer Sunset farmer’s market, he bakes in the Dogpatch out of Schilling Co. and sells his baked goods such as squid ink-infused chili and cheese rounds and cinnamon bread at Upper Cut at Spark Social. Harmon’s love of local ingredients is very Californian. But his story of scouring the area for primo water is singular. “I thought it might be fun to do something with that,” Harmon says. “There’s great sourdough conditions all along the West Coast.”

After a brief affair with baking in college, his passion (and business) really began once he retired and took a few classes at the San Francisco Baking Institute. All of his breads are named after the old missions in the area, and his ingredients all come from California. He prefers olives from Santa Barbara and walnuts from Old Dog Ranch in Montara. He got in touch with Vacaville’s Soul Food Farms, the egg supplier for Alice Waters. Then he turned to heirloom flours and is getting his from Capay Mills, same as the new pizza outfit Angie’s in the Mission. It was the University of Washington’s approach, though, that led to his fascination with water quality. Rather than ancient grains, which haven’t necessarily kept up with modern palettes, the UW says it’s water that makes San Francisco bread distinctive. Ever since 1913, though, the Sierra-source water in Hetch Hetchy is controlled by Pacific Gas and Electric and can only be used for “public interest.” Even if a small business could access the reservoir, it’s been altered since 1942 with fluoride and various sanitization practices. “The tap water is pretty useless for bread,” Harmon says. “It’s okay, but if you’re a fanatic like me then not so much.”

Bear Flag Bakery

Greg Harmon

Unrelated to all his searching, Harmon worked as an insurance inspector. While on the job in the Bayview, Harmon encountered Albion Castle. It was built in 1870 and has two-foot thick walls. “That’s military,” Harmon says. “You can mount a cannon on the roof and shoot into the Bay.” More relevantly, a military outfit like this needs its own water supply. For many years the building was a brewery, but the owner showed Harmon the cisterns. Half a million gallons of San Francisco water runs from the location into the bay, all of it glacier blue. Basically, it’s a water aquifer that pre-dated the 1913 public use litigation that’s slowly draining into the Bay. “It’s mind-boggling,” Harmon says. “It has some issues, mostly biomaterials, but it’s actual San Francisco water.”

He asked the owner if he could use the supply for his baking interests, and the owner said it was no problem. About a year and a half later he began making his sourdough with it, and Harmon couldn’t believe the results. “It was the best bread I’d ever made,” Harmon says. Sadly, the relationship didn’t last — it wasn’t worth it for Albion Castles to work with such a small business — so Harmon turned to spring water in Sonoma. His nephew owns Argot Vineyards in the county that Harmon sources from now, his quixotic pursuit ongoing. When his nephew is busy, he gets the standard 40 gallons he sources each time from a different outfit; sometimes he goes for Mayacamas Spring Water Co. (which pulls its water from Cobb Mountain up by Cloverdale), and in the third weekend in November he sourced from Frost Watch Vineyards. He says Tartine is great, as is Semifreddi and Acme, but thinks his distinctive style of only winery and spring water makes his bread standout. “We’ve got a lot of sourdough bakers in the area right now,” Harmon says. “But I like my bread. I think I’ve got a good style.”

Bear Flag Bakery is on-site at the Outer Sunset farmer’s market every Sunday, and available for custom order through its website.

Greg Harmon