In a white-walled room deep inside a southwest Santa Rosa building once used to manufacture heart stents, 11 specialized machines to extract concentrated cannabis rumbled, hummed and popped in production for California’s largest legal marijuana manufacturing operation. 

Five months ago, law enforcement officers hauled away extraction machines and other equipment worth about $3 million from the Circadian Way facility, halting production and forcing the company, CannaCraft, to address a series of code violations. One of its founders, Dennis Hunter, was briefly jailed.

Since then, California and the city of Santa Rosa have begun embracing cannabis manufacturing with new regulations that allow producers of medical marijuana-infused products to operate openly. And state voters legalized recreational use of marijuana, adding to the system of regulations advocates hope will bring marijuana businesses into the mainstream. 

CannaCraft this week received a final level of approval from the city of Santa Rosa to run its...