When considering microbial stabilisation options for a brewery, there are many obvious considerations, from initial set up cost to the impact on overall beer quality.
Many modern brewers are moving away from pasteurisation to cutting-edge techniques such as sterile filtration (also known as cold stabilisation) due to reduced overall costs. Those still pasteurising their beer should look to the additional benefits of cold stabilisation in order to help their brewery processes stay future-proofed.
One of the beneficial side-effects of sterile filtration using a filter such as Parker's BEVPOR BR is that it is more environmentally friendly than flash pasteurisation, and in turn, this can impact on how much of a brewery’s income is spent on operational costs.
With energy and water costs set to increase in most nations, brewers are being driven to implement process efficiency improvements to remain sustainable.
Large savings can be made in both water consumption and electrical energy consumption when using sterile filtration during the brewing process.
Flash pasteurisers work by passing the beer through a plate heat exchanger (PHE) at a required flow rate. During the pasteurisation process, it is critical that a constant flow rate is achieved in order to ensure that pasteurization is correctly achieved. If at any point, the flow rate, pressure or temperature change, the system is usually held in a standby setting, and the beer is replaced with an equal quantity of flowing water until the problem is rectified. This can result in huge quantities of water being used in the process.
Sterile filtration is a much less volatile method, as there is not such a high demand for a reliable flow rate, temperature, or pressure. This means the annual water consumption of a cold filtration system can be many times smaller than that of a pasteurisation system.
In addition, in the pasteurisation process, the hold-up volume inside the PHE is much larger and this contributes to much higher mixing phases in comparison to sterile filtration. As such, every time there is a batch change, the water consumption far outweighs that associated with sterile filtration.
In today’s environment, where brewers are having to be flexible and adapt to market conditions – for instance by introducing new products to meet changing tastes and keep up with the competition – there is a requirement to change the products being packaged more frequently. In this environment, the water consumption and hence the associated increase in OPEX for flash pasteurisation over sterile filtration will become more pronounced.
Electrical energy consumption
With the flash pasteurisation process typically heating beer to around 70°C (158°F), the electrical energy costs of doing so can also be significant.
Not only this, but Henry’s law states that the amount of dissolved gas is proportional to pressure – and by increasing temperature of the beer, the pressure increases. This causes CO2 to be released by the beer as the temperature increases. Unless the pressure is tightly controlled with booster pumps, the beer will lose its carbonation and need to be re-carbonated.
The pumps which prevent this from happening by keeping the beer pressurised operate at 10 – 14barg, which consume a further significant amount of electrical energy.
With sterile filtration, as long as the line pressure is maintained at approximately 1barg – significantly lower – there is no requirement to run booster pumps. The electrical energy demand and hence operating costs are significantly reduced compared to pasteurisation.
Parker Bioscience specializes in protecting the quality of beer at the lowest cost, and sterile filtration (or cold stabilisation) is a great way to do so. In like for like process conditions (same flow rate, same capacity), you could reduce your operating costs by up to 44% by choosing filtration as an alternative to flash pasteurisation.