With just six seats, available by reservation only, Theorem may just be Costa Mesa's most intimate bar.
But alcohol-laden trendy cocktails aren't the draw — the focus will be coffee.
"Like beer, like wine, like fine spirits, coffee deserves a spot on the podium alongside those," owner Jeff Duggan said about the concept behind the new coffee bar. "It's very complex. If you look on terms of complexity, coffee trumps all of those."
Theorem opens in early September, near Portola Coffee Lab in the OC Mart Mix, on Hyland Avenue in Costa Mesa.
Duggan and his wife, Christa, own both shops.
While Theorem's beverages won't contain alcohol, some will take inspiration from vintage cocktails, like the Old Fashioned.
At the coffee bar, the drink is a combination of barrel-aged, cold-brew Kyoto coffee, muscavado simple syrup, coffee-based bitters and an orange garnish.
"We can create this beverage with just coffee — no alcohol at all — and have it be as tasty, if not more tasty, than the original drink itself," Jeff Duggan said.
The Kyoto, which so far has been aged in an oak cask for six months, may appear in other drink recipes, he said.
The menu, a prix-fix of $15 that will change weekly, could contain items like liquid-nitrogen affogato and coffee flights.
The affogato is Theorem's twist on the classic Italian espresso-over-ice-cream dessert, made-to-order in front of the customer, while the coffee flights will feature a mix of specialty brews.
"Coffee can really be great just by being coffee," said Truman Seversen, director of research and development for Portola and Theorem. "With Theorem, we're taking a step back and, while keeping that mindset intact, we're thinking of coffee not just as an end-all but also as an ingredient."
After Theorem gets going, the menus will also incorporate food pairings, he said.
That, coupled with the close proximity to the barista and intimate nature of a six-person bar, creates a total culinary experience, Severson said.
While it is possible to sit at Theorem for a short while, Seversen expects most guests will stay much longer. Most of the beverages are made-to-order, so the process can be time-consuming and intimidating to the uninitiated.
"We ask our patrons to take some time with us," he said. "They choose to come visit us and we ask them to let us cater them though this experience."