Kungsholmens Kvartersbryggeri is started in Stockholm by a group of beer enthusiasts and homebrewers. This is in response to the limited supply and the less flavorful beer. The brewery is named after the owner's childhood idol and grandfather, Nils Oscar.

In 2006 Nils Oscar outgrows the premises on Kungsholmen and the brewery moves to Fruängskällan in Nyköping, we feel at home here. When the brewery has reached its maximum capacity of 1,000,000 litres in 2013, another expansion starts, out with the old and in with the new. We now have a modern brewery and equipment that makes us very quality assured.