Batch 19 is back.

After spending four years on ice, the pre-Prohibition style lager based on a historic recipe unearthed in the basement of the Golden brewery is now available in select bars and restaurants in Colorado.

AC Golden Brewing Co. is reviving the unpasteurized lager to commemorate the 100th anniversary of the ratification of the 18th Amendment, which prohibited the sale and consumption of alcohol. For now, it will be available only on draft and only in the brewery’s home state.

“We wanted to do something special for Colorado beer drinkers,” says David Coors, president of AC Golden. “Given how many people have been asking us about Batch 19 over the last few years, bringing it back was an obvious choice. More than 100 years ago, my great-great-grandfather had a vision of a flavorful and perfectly balanced lager that he could share with the people of Colorado. We’re thrilled to make that vision a reality again.”

The 5.5 percent alcohol-by-volume deep golden lager is brewed using noble hops and two malts to deliver a biscuit aroma backed by spicy, herbal notes. It is based on a recipe found in an old logbook discovered years ago.

Coors Brewing Co. first released Batch 19 in 2010 in select markets nationwide. After priorities shifted in subsequent years, the brand was pulled from the market in 2015. And drinkers have been asking for it ever since.

“Two hundred fifty thousand people go through our Golden brewery every year, and our staff tells us that the No. 1 question they get is ‘what happened to Batch 19,’” Coors says. “There’s clearly demand for it in the market, and on top of that, it was an employee favorite in Golden, known as ‘Pre-Pro.’”

Coors promises AC Golden will take its time with the brand, controlling production and distribution so that Batch 19 doesn’t get too big too fast. If all goes well, the next step is packaging. Beyond that? “There’s no constraints on how big it can get,” Coors says. “It’s really a delicious and unforgettable beer, and people miss it.”