Lesson 8 - Clarification – Filtration
This lesson discusses the process of beer clarification via filtration. The filtration process primarily removes suspended particles from the matured beer to produce a clear stabilised beer that is ready for packaging. This lesson also discusses the importance of this process, the different filtration technologies available to the brewer, and the impact of filtration on final beer quality.
Point of Reflection – Reconvene
Welcome back. So, what were your thoughts?
Let us summarise and compare the characteristics of DE vs cross-flow filtration technologies:
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Diatomaceous Earth (DE)
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Cross-flow Filtration |
| DE suppliers sell plant and service packages. It is in their interests to optimise filtration run performance at the optimal DE usage. | The business model of this category of technology supplier is that they sell membranes. Their on-going revenue stream depends on selling membranes to replace used ones. |
| DE is a mature technology. A number of manufacturers currently offer the same or similar technology. | A relatively new technology. The main aims are to improve filtration run length, increase membrane life, drive improved plant reliability and reduce operating costs. It is likely that there will be advancements in this area. |
| DE filters are considered to be very flexible; they can be manipulated to cope with and filter varying beer qualities. This necessitates a high degree of skill and experience to make the necessary adjustments to precoats, bodyfeed rates, and bodyfeed grade. | These are absolute filters; no matter the input, they give exactly the same output each and every time. Far less operator knowledge is required to control filtration; very suited to the ‘black box’ approach and thus to automation. |
| DE is widely available and can be sourced from many places. Filtration septa (e.g. candle spares) are proprietary, although these would need to be changed very infrequently. | There are currently very few cross-flow filter manufacturers; they all produce their own membranes. Supply is thus limited to the manufacturer of the filter unit. |
In summary, as breweries look to invest in new filtration equipment to improve brewery capability, increase throughput, and improve product quality, installing a cross-flow filter would help future-proof the operation. This technology is already challenging the filtration performance of a DE filter and it will continue to evolve over time. From a sustainability and environmental perspective, there may be pressure for brewers to move away from DE usage; cross-flow is a promising alternative.