The deal is effective on November 30.
Brewery founder Richard Emerson said the brewery would remain as a standalone business unit within Lion and would continue to produce the same "great beers" from the same brewery with the same people.
Lion NZ managing director Rory Glass said Emerson's complemented Lion's existing beer portfolio well.
Lion brews Speight's in Dunedin and is the Rattray St brewery is undergoing a multi-million upgrade to cope with increased demand and a lack of capacity in quake-damaged Christchurch.