Filtration in brewing

Beer is filtered to remove the sediment left over from the brewing process. It is necessary to remove these fine particles in order to improve not only the physical appearance of the beer but also its taste and aroma.

Filtration uses finings which are substances added towards the end of the brewing process. There are many types of finings with varying properties which act in different ways to improve the final quality of the beer.

Diatomaceous earth, also known as kieselguhr, is an abrasive substance commonly used in brewing as a filtration method because of its excellent ability to remove the unwanted particles (including residual yeast) and produce the required consistent appearance and taste. It is usually added after the fermentation and maturing stages.

Other finings include polyvinylpolypyrrolidone (PVPP) and silica gel. These are used to extract impurities to remove haze and produce a clear finished product.

Accurate, robust dosing and transfer

To achieve the desired quality, the kieselguhr or PVPP needs to be dosed accurately. This is essential to ensure consistent beer flavor and appearance. Customers expect a given beer to always look, taste and smell the same.

Peristaltic dosing pumps from Watson-Marlow Fluid Technology Group (WMFTG) are extremely accurate and repeatable. The flow is unaffected by variations in fluid viscosity or pipework. This avoids the need to overdose costly finings to ensure an adequate amount is added, thereby minimizing costs.

Finings, in particular diatomaceous earth, can be abrasive and therefore cause premature wear to many pump types. This is not a problem when using our Bredel range of hose pumps for finings dosing as they can easily handle abrasive fluids without wear, thereby reducing maintenance costs and downtime. Additionally there are no valves or seals to block eliminating costly downtime and simplifying maintenance.

As well as dosing kieselguhr, PVPP, silica gel or other finings, WMFTG’s Bredel peristaltic hose pumps are used very successfully for removing the filtered slurry from the process. This slurry is abrasive and can be very viscous making it difficult for other pumps to handle. This is not an issue for our hose pumps which, in addition to abrasives handling, have excellent suction capabilities. They are capable of a suction lift up to 9.14m (30ft) and are self-priming. They can also run dry without damage.