The shelf-life of beer is a key consideration for any brewing business – and there are multiple ways of extending this. It can be achieved through ingredient selection, packaging, or the brewing methods used during production.
The overall stabilisation of beer is of critical importance for the shelf-life of beers. As producers target new and faraway emerging markets, it is critical that the beer reaches drinkers’ palates with the characteristics that its creators have spent so much time and resources developing intact.
Traditionally, this has been done on a large scale by flash pasteurisation, a process of heating the beer which removes spoilage organisms that can be present. The typical spoilage organisms within beer include yeast – both wild, and those used in the brewing process – as well as specific anaerobic bacterial strains (most commonly lactic acid and acetic acid species). Pasteurisation, though an effective means of removing microbials can, however, negatively impact the flavour profile of the end product, and often reduces the shelf-life.
Sterile filtration is an alternative to pasteurisation, which has many of the benefits, but fewer of the drawbacks. Sterile Filtration (or cold stabilisation) refers to the final microbial filtration of beer using a microporous membrane to remove yeasts and other spoilage organisms. More and more brewers are turning to sterile filtration as a reliable method to ensure a longer shelf-life of their packaged beer.
It has been shown that beer which has been filtered to achieve stabilisation retains its unique and desirable characteristics more efficiently than beer stabilised through flash pasteurisation. It can also be demonstrated that sterile filtration can have a beneficial effect on taste characteristics throughout the duration of the beer’s shelf-life.
Parker Bioscience’s BEVPOR BR microfiltration filter not only ensures the microbial stabilisation of beer, it also helps to protect its unique sensory characteristics. Utilising a PES (polyethersulphone) membrane, The BEVPOR BR minimises the adsorption of beer components when compared to alternatives.
The pasteurisation process is a much harsher technique than sterile filtration, which has a gentler impact on the beer.
Sterile filtration increases the shelf life of a product, whereas pasteurisation, even for short periods, can lead to a decrease in shelf life.
Because of the relative simplicity of cold stabilisation systems compared to pasteurisation equipment, the performance of sterile filtration can more easily be monitored.
The filters used in sterile filtration minimise adsorption of desirable components and help to protect beer head retention.
Differences in the mixing phase mean that beer losses when using sterile filtration can be significantly lower than flash pasteurisation. This is mostly due to losses caused when beer is dumped following a shutdown of a pasteurisation system if any abnormalities in pressure, temperature or flow rate occur.
Sterile filtration does not require the huge amounts of energy needed to run the plate heat exchangers used in pasteurisation and does not necessitate a buffer tank, resulting in less water consumption than that which is typically seen in the pasteurisation process.
Sterile filtration works just as well in removing microbial growth as pasteurisation and generates fewer of the drawbacks.
Sterile filtration requires fewer parts, making it easier to operate. Filters can often be regenerated in-situ, resulting in a longer service life.
Pasteurisation hardware is large and expensive in comparison to the lower initial outlay for a sterile filtration setup.
This post was contributed by Daniel Vecsey, market development manager, Parker Bioscience Division, United Kingdom.
Parker Bioscience Division offers filtration solutions to protect the quality and taste of beverage products. By working with our application experts, manufacturers can develop a tailored solution to ensure their beverage is free from contamination, full of flavour and visibly clear.