IN NORTHERN California—a place awash in craft-beer consciousness—there’s still a surprise to be found at Freewheel Brewing Company’s Redwood City pub: a proper pint.

That is to say, cask beer. The traditional British style—called “real ale” across the pond—is served fresh from a wooden barrel, traditionally, or a metal cask, more common nowadays; kept at cellar temperature (50-55 degrees versus a refrigerator’s 35-40); and lightly carbonated by the digestive action of living yeast. Yes, compared to a brisk, bubbly keg pour, it’s warm(ish) and flat(ish). But, the style’s devotees argue, a pint produced this way is far richer in the subtle flavors lost with over-chilling.

Casked beers have been slow to catch on here among our chilled kegs, “frost-brewed” bottles and “cold-activated” cans. Like a keg, a cask is distributed to a bar and tapped there for customers. But because the natural carbonation in a cask-conditioned beer is gentler, a hand pump, moved up and down repeatedly, is required to pull the beer from the cask, whereas a keg’s contents, pressurized artificially with carbon dioxide or a mix of CO2 and nitrogen, are forced out with a simple trip of a valve built into the lever-like tap. A cask is also fussier than a keg, doesn’t travel as well and stales quickly once tapped. Nevertheless, casked beer is finally taking hold in the U.S., found not only at the breweries that make it but also at bars across the country.