Unlike so many modern bars that aim to transport guests to a far-flung locale or down a figurative rabbit hole through their thematic drinks and menus, San Francisco’s True Laurel relies on its local bounty, often through foraging, to firmly plant guests where they are: the Bay Area.

To evoke that sense of place, what True Laurel can’t forage themselves, they carefully source from nearby producers. For example, in The Doctor Away, a rum cocktail that is featured in the fall, the bar forages sappy, green pine cones to macerate in vodka and re-distill; sources lovage from Napa Valley–based Jackson Family Farms; and gets Granny Smith apples, which are juiced for the cocktail, from a farm just south of San Francisco.

Once the components of a cocktail are no longer available, it gets rotated off the menu. But the most popular drinks do come back around annually when the ingredients are back in season, with a few minor tweaks. One of these fan favorites is the nostalgic LDC Highball, a whiskey-Coke with panache.

“It all starts with a classic cola formula I have been using for years,” says True Laurel owner Nicolas Torres, whose go-to is a late 19th-century recipe. Made with a laundry list of ingredients, the cola is processed in two phases—not only to get the best out of the many elements used, but also to do so safely.

The most peculiar botanical used in the cola is the leaves from the Islais Cherry tree (also known as Prunus ilicifolia), an evergreen plant native to the Bay Area. “I learned about this tree over 20 years ago when I used to teach environmental justice and native habitat restoration for the city’s parks department,” Torres says. “We personally go out and forage this plant along creek beds tucked within the city.” He notes that few, if any, other bars and restaurants use the ingredient because it’s both difficult to find and often intertwined with poison oak, which makes harvesting it more complicated. The amygdalin-rich leaves, too, can be poisonous if not treated properly.

“Amygdalin is the compound that produces that beautiful amaretto flavor—the same compound you find in stone fruit pits like apricots and cherries,” says Torres. “Eaten raw, it would produce cyanide in the belly and can be very toxic,” but True Laurel breaks down the volatile compound by heating it, rendering it safe for consumption and full of marzipan flavor.

But because the tree leaves require intense heat, Torres processes the brighter ingredients first to maintain their vibrant flavors in the syrup. That first phase blends lime, lemon and orange peels with sliced kumquat, lavender, fresh ginger and simple syrup. The mixture is cooked in a Gastrovac, a tool that can lower the atmospheric pressure within a pot set on an induction burner, offering a gentle boil at a lower temperature.

The other half of the cola syrup is made by combining the leaves with citric acid, cinnamon, star anise, tonka bean, vanilla and “a little chamomile” with more simple syrup, which is cooked at a high temperature in an immersion circulator. When both syrups are finished and cooled, they’re strained and combined to form the drink’s foundation. 

The cola syrup is batched with a blend of whiskeys—Dickel 8-year bourbon and Three-Chamber rye—a collaboration between Dickel and the Leopold Brothers. (LDC stands for Leopold, Dickel and Coke.) Amontillado sherry adds dryness and nuttiness, and citrus juice and water are used for dilution. “At that point it tastes good, but looks like a murky Coca-Cola,” says Torres, so the batch is treated with fining agents—namely pectinase, kieselsol and chitosan—to clarify naturally, before being spun through a centrifuge for maximum yield. Finally, the clarified, pre-diluted batch is force-carbonated and served in a glass with slices of kumquat. 

The LDC Highball is a nostalgic drink that Torres describes as the best whiskey-Coke he’s ever had. The high-low, hyperlocal cocktail is befitting of the bar, too. “It’s based on a classic, so, although it reads nerdy, we can tell people it’s a whiskey-Coke at the end of the day,” he says. “The technicalities behind the drink are in the background, but they lead to a perfect finish.”