Since in continuous fermentation the tanks are emptied less frequently there are fewer CIP cleaning cycles, as well as savings and reduced losses at the wort transfer stage; CO2 recovery can also be increased.
Neutrabling-based Krones said a model system they are exhibiting at Brau Beviale 2014 this week is based on research underway at the State Testing and Experimental Institute for Brewing Technology of Munich-Weihenstephan.
120 hectoliter pilot plant planned
The next stage of research will see TU Munich’s (TUM's) experimental system being put to the test, as the partners test a pilot plant with a daily output of 120 hectoliters.
Krones said replacing batch mode with continuous process for beer production has not proved successful to date due to the complexity of beer and its byproducts.
The TU Munich system uses a ‘tank cascasde’ – cylindro-conical tanks used for batch mode fermentation are connected via a central guide pipe, as well as filling and draining pipes at the tank dome and tank cone.
Smaller systems, reduced production costs
Krones said this design permitted a continuous fermentation process under similar conditions to those obtained using traditional processes, with a focus on simplicity and the metabolic needs of brewing yeast.
‘Green’ beer is then conveyed from one tank to the next via a pressure gradient – ensuring gentle conditions for the yeast, while sediment can be removed from below then used again as pitching yeast of thrown away.
“Overall, both significantly lower capital investment costs thanks to using smaller systems and reduced production costs can be achieved, while maintaining a consistently high level of product quality,” Krones said in a statement.
It added that continuous process equipment can be retrofitted to existing fermenters.