It took nearly two years and 80 different types of coffee beans, roasted three different ways, for Annalise Zimmerman, co-founder of Emerald Hills Cafe & Roastery, to develop a cold-brewed coffee that met her standards.
The combination that finally passed muster is made painstakingly slowly in a yama tower, a contraption reminiscent of a physics experiment, that allows water to drip through coffee grinds one drop at a time. The result: smooth, deep, highly concentrated cold brew coffee. This is not the much easier, cost-effective method of putting coarsely ground coffee beans into a cheesecloth and steeping it in water for 24 hours. Zimmerman said she doesn't like the "sour," almost metallic flavor that this process tends to produce.
"It took us that long to finally have something we enjoyed," she said. "That's how stuck we are on making sure what we serve is really, really good coffee."
Located high in the winding hills above Redwood City, next to a taqueria and across from a vacant lot, Emerald Hills is an unassuming neighborhood cafe pouring cups of carefully crafted, third-wave coffee.
Third-wave coffee refers a return-to-roots, artisan approach to brewing coffee popularized by companies like Blue Bottle Coffee in Oakland and Stumptown Coffee in Portland. The term typically conjures up images of trendy shops serving expensive, highly Instagrammable cups of coffee.
Emerald Hills Cafe offers a refreshing contrast but with the same high quality coffee expected at third-wave shops.
Zimmerman, a 22-year-old Mountain View native and self-described coffee fanatic who can answer pretty much any question about coffee, helped transform the cafe into what it is today. Co-founder Rainer Johnk -- a paint contractor with no background in coffee but a tenacious dedication to making coffee "the right way" -- hired her after taking over the shop from his stepson. Zimmerman has been working in and around coffee since she was 15 years old, including at Peet's Coffee, a Stumptown coffee cart at Emily Joubert in Woodside and Highnote Coffee in Woodside.
Together, the two worked to restore the cafe's reputation in the neighborhood, replacing almost all of the equipment (save an original coffee roaster) and completely revamping the coffee itself. Out with the classic dark roast and in with the single-origin coffees sourced from everywhere from Bali to Kenya.
"The very first thing that we changed was the coffee. Coming from a third-wave background, I envisioned treating coffee like wine, especially since it's four times more complex than wine," Zimmerman said, referring to the more-than 800 volatile aromatic compounds in coffee, compared to wine's count of 200. Those compounds are "what our bodies pick up on to figure out how things taste," like smells and flavors, she said.
Emerald Hill roasts all of the beans in-house, and Zimmerman spends time with each bean varietal to figure out how to best "caramelize the sugars within the beans so the best flavors can come out and play." They search all over the world for small farms to support, like a women's cooperative in Bolivia. They don't buy from large, corporate-owned farms, and don't insist on expensive certifications like USDA organic or Rainforest Alliance --where farms are "audited annually against a rigorous standard with detailed environmental, social and economic criteria," according to the organization's website -- that some smaller producers can't afford, Johnk said.
"To me, third wave means coffee with a consciousness to it," Zimmerman said. "We go out of our way to develop a connection to know our farmers, our staff, and our customers and it's a continuous line of respect and care from origin to the final cup, and that fuels our obsessive passion for high quality and standards."
The Emerald Hills menu changes frequently depending on what's available. On a recent afternoon, the menu listed coffees from Rwanda, Guatemala, Bali, Zimbabwe, Ethiopia, Colombia, Costa Rica and other regions. The cafe also recently started serving fresh pastries from local bakeries, including Douce France in Palo Alto.
The third-wave philosophy, however popular in the Bay Area, was not immediately embraced by some longtime Emerald Hills customers who were wary of the trend, and what it meant for the kind of coffee they had been drinking for most of their lives.
"When we decided to go third wave, it upset a lot of people, a lot of regulars," Johnk said. "We have to do a lot of talking to people and tell them why we do what we do. We both figured the only way that we're going to keep up the energy to keep doing this is doing it right.
"We do it right or we don't do it at all," he said.
Part of doing it right is staying approachable -- what Johnk called "coffee without eye-rolls."
"What I found in the third-wave coffee world is that it's very hard to approach people sometimes about talking about coffee. I really did not like that," Zimmerman said.
They encourage customers to ask questions about coffee. They also offer events for local companies and in the future, plan to host classes and free tastings at the shop.
Despite their passion, it's clear the path to third wave hasn't been easy at this small, out-of-the-way cafe.
"We're constantly coming up to these crossroads where we go, 'we could just buy a Home Depot bucket and make cold brew by the gallons,'" Johnk said. "We're just hoping doing it the right way actually will pay off -- and it's the only way we want to do it."
Emerald Hills Cafe & Roastery
3203 Oak Knoll Drive, Redwood City
Hours: Monday-Friday, 6 a.m. to 6 p.m.; Saturday, 7 a.m. to 1 p.m.; Sunday, 8 a.m. to 1 p.m.