Brewery leads on environmental impact but seeks to do more Members of the Sawmill brewing team in front of the grain silos that eliminate the need for 12,000 plastic sacks each year. Sawmill Brewery’s dedication to taking care of the environment has already won it international recognition, but for owner Kirsty McKay the journey does not stop there. Two years ago, the Matakana brewer became a Certified B Corporation, demonstrating that it had reached the highest standards in terms of environmental impact, transparency and accountability. That meant it became one of a small number of New Zealand companies to be certified and the only New Zealand brewer to do so.