Certa Sine pumps from Watson-Marlow Fluid Technology Group (WMFTG) have replaced rotary lobe pumps at a brewery in Germany, eliminating gassing issues and boosting pump efficiency.

In the brewing process, once fermentation is complete, the yeast is recovered (or harvested) for re-use. However, much of this yeast settles at the bottom of the fermentation tank where it can set into compacted bulk so pumps with high suction capabilities are required to draw the solid yeast from the tank.

Gas Locking

Yeast naturally forms bubbles during fermentation and can cause gassing-off (gas locking) issues for the pumps used to harvest it. Gas locking had serious and ongoing effects for the lobe pumps at the brewery, including a reduction in flow rate. This effect was particularly noticeable due to the need for long suction lines between multiple yeast tanks and the pump station.

To overcome these challenges, the brewery invited WMFTG to assess the application and make its recommendations. Several stipulations were involved, including the requirement to handle various yeast viscosities, the need for self-priming, and no gas locking. With these thoughts in mind, the brewery was advised to adopt a Maso-Sine Certa 200 series pump.

Certa offers both high suction capability and high flow. This performance level is consistent even with different yeast strains/viscosities and pipework runs. In fact, even compacted yeast is easily drawn from the fermentation vessel.

Controlled process

Certa pumping technology is virtually pulse-free, providing consistent flows despite varying product and system conditions, thus facilitating controlled yeast transfer. Due to the continuous and smooth pumping action, the pump draws the yeast from the bottom of the tank and avoids any turbulence that would cause the beer to mix with the settled yeast. This clarity enables the brewmaster to recognize immediately when the yeast removal process is complete and can stop the pump before losing beer.

A further advantage of Certa technology is low-shear pumping. The presence of high shear can lead to poor quality beer, as well as high yeast usage and costs – issues avoided with the use of Certa pumps.

It was a combination of these factors that prompted the brewery to install Certa 200 pumps, which duly led to successful and continuous yeast harvesting. The brew-master has since stated that ease of maintenance by the brewery’s personnel, and rapid CIP cleaning, are added advantages. Here, the simplicity of the Certa pumps reduces CIP cycles and the amount of water and cleaning agents required.