Bulk-dispensed cocktails, anyone?Bulk-dispensed cocktails, anyone?

Last August, bar manager Kevin Diedrich debuted the first batch of Negroni cocktails on tap at Jasper’s Corner Tap & Kitchen in San Francisco. More than 2,000 orders later, the gin, Campari and sweet vermouth aperitif is the eatery’s best-selling drink, with no more promotion than a chalkboard and word-of-mouth.

Off-duty workers from other restaurants were the first Negroni fans, but soon joining them were customers of all stripes, including many who until then were not cocktail drinkers, said Matthew Meidinger, general manager of Jasper’s, a Kimpton Restaurants concept.

“This drink hasn’t even been in our cocktail book until very recently, and it has been consistently among our top sellers,” said Meidinger. “I think it is entirely due to ...