The use of open fermenters was traditionally the brewing industry norm until the early 20th century. Most were rectangular wooden vessels with little or no temperature control.

The influence of Swiss-German inventor Dr Leopold Nathan and the rise of mass-manufactured stainless steel resulted in the new industry standard: cylindro-conical vessels (aka uni-tanks). Initially designed for brewing in tropical climates, the so-called Nathan systems first arrived in Australia in the 1920s, with Cascade Brewery (Hobart), Walkerville Brewery (Adelaide) and Richmond Brewery (Melbourne) amongst the early adopters.

Combining strict temperature control, more efficient removal of trub and spent yeast, and superior spatial optimisation, the cylindro-conical vessel rapidly became the face of the modern brewing industry. It went hand-in-hand with the upscaled industrialisation of beer production; but what overall effect did it have on the flavour of beers which had previously been brewed in shallow, open fermenters?

Around the world, pockets of traditional open-fermentation still exist, with Trumer Brewery (Austria), Samuel Smith (UK), Schneider Brewery (Bavaria) and Anchor Brewing (USA) being notable examples. At Seven Sheds Brewery we used shallow open fermenters out of necessity, then grew to appreciate the fruity esters which resulted and which became our house signature. White Rabbit, Bruny Island Beer, Wildflower, La Sirene and Cosmo are other local breweries who have embraced the open vessel regime. Now a new wave of craft producers is experimenting with brewing lagers in open wooden fermenters, seeking novel points of difference in their beers.

Could open fermentation be the new beer frontier?