Saoirse Stephan | Jan 16, 2023
Over the years, we've all heard some bizarre pump myths. Some brewers still avoid using pumps for fear of damaging their product. We're here to dispel some common myths about brew pumps once and for all!
1. Pumping destroys wort
There is nothing intrinsically wrong with pumping wort with a centrifugal pump. This belief usually comes from a fear of the effects of shear – and centrifugal pumps are high shear. While this can create issues in specific contexts, or where centrifugal pumps are incorrectly operated, for most brewers this is not an issue.
2. Centrifugal pumps are prone to damage
Centrifugal pumps are widely used for pumping beer all over the world, but some small brewers believe they are problematic. With proper seals, regular monitoring, and a VFD, any damage is extremely unlikely. Only if the centrifugal pump is mishandled or ignored will damage occur.
3. Pumping destroys head retention
If not done correctly, pumps can cause CO2 to escape from the beer. It is critical to keep carbonated beer cool and under pressure when pumping it. The colder the beer, the harder it is for the CO2 to escape from solution.
In most cases, poor head retention is caused by poor cleaning techniques or a lack of foam-forming compounds in the beer to begin with. The first step in resolving head retention issues is to ensure that your equipment is properly cleaned.
4. A self-priming pump does not exist
This is simply false. Self-priming pumps are used in a variety of industrial and commercial settings, including wineries and breweries. Our RF and AODD pumps are both popular self-priming pumps.
If your self-priming pump is not working properly, check to see if there is an air leak in the suction line, debris in the impeller, or if the pump has become air bound.
5. Pumping collects massive amounts of dissolved oxygen
False. The most common sources of air pickup in beer processing are tank transfers, stabilizer addition, and bottling. If you suspect that your pump is causing dissolved oxygen, inspect the lines to ensure that there are no leaks in the production line. Particularly on the prior to the pump, this is where you can suck air in to the flow.
Some good practices to avoid oxygen pickup are making sure the transfer lines and joints are tight, minimizing cold side transfers, ensuring the beer entering a receiving tank is at a low velocity to avoid turbulence, filling your transfer lines with water before beginning any transfer, and finally, regular inspection and cleaning of the filling valves.
6. Centrifugal pumps don't suck, they push
Centrifugal pumps excel at pushing rather than sucking. Atmospheric pressure pushes liquid into the pump by lowering pressure on the pump's suction side. This means, you can only suck up to 1 atmosphere (14.7 PSI), but you can push at much higher pressures, 3 x or more depending on the size of the pump.
7. Any pump capable of handling your product will suffice
A pump's ability to handle a specific product does not imply that it was designed for it. This is particularly true for beer. You shouldn't use a water pump to move beer just because you can. A water pump will cause too much shear and will be difficult to clean.
8. Air can leak into your brew pump
Pumps are a high-pressure point in the brewing process, so liquid would leak out rather than air in. If air is entering your system, it is doing so prior to the pump.
Air can enter the flow through suction line leaks at elbows, hoses, joints, etc prior to the pump. Air can then become trapped in the volute of a pump, reducing capacity and causing vibration and noise. To correct this, turn off the pump and open the vent valve to allow the air to escape."