Applications
- Physical Stabilization
- ensuring haze-free, longer lasting beer
Stabilization of beer is not a discrete operation. It is a gradual progression of procedures aimed at optimizing the removal of undesirable content at each stage of production. In dealing with physical, chemical and microbiological stability, the selection of raw materials and the design of the brewing processes play a large role in ensuring final product quality.
Physical stabilization is the process of preventing hazes and deposits from forming after the beer has been packaged. This can be achieved by removing constituents that will eventually lead to haze formation, such as certain proteins and polyphenols, or by accelerating the formation of hazes and deposits so that they can be removed prior to packaging.
Typical methods of removing haze precursors are the addition of fining agents, or filtration using adsorptive powders such as diatomaceous earth (DE) or polyvinylpolypyrrolidone (PVPP). The porous screens, sheets or candles that are used to support the powder as it is dosed into the beer will always allow some powder through and trap filters should be positioned downstream to prevent this powder from reaching final storage and packaging. Alternatively, the DE and PVPP may be incorporated into a cellulose fibre matrix that is then cut into preformed sheets or assembled into stacked disc (or lenticular) cartridges This may be a more convenient method of stabilization and produces a higher degree of clarity to the beer.
Trap filtration is usually achieved using clarification filters with retention ratings between 5 µm and 15 µm for DE trap and 5 µm and 25 µm for PVPP. Medium and fine grades of sheet and lenticular filters will provide high product clarity and good physical stability.
Once the beer has been physically stabilized, further treatment usually involves assuring microbiological stability and polishing to provide bright clarity.
- Strong, washable cellulose sheets support powder precoat in plate and frame filter presses.
- Trap filters remove small quantities of powder released from upstream processing and protect the process in the event of major bed collapse.
- Adsorptive filter sheets and lenticular cartridges provide clarification and physical stabilization.
- Designs that optimize performance in forward flow and backwashable applications.
- Standardization and Intermediate Stabilization
- protection during storage and transport
Whilst alcohol and hops serve to stabilize the beer to some extent during short-term storage or transport the beer may still be susceptible to further microbiological activity. This can be due to continued fermentation by residual brewing yeast; yeast autolysis; ingress of wild yeasts or the activity of many other bacteria.
Preventing the ingress of extraneous organisms can be achieved by minimizing the head space in storage vats and transport tanks and ensuring that sterilizing filters are fitted to tank vents and in feed lines for top pressure carbon dioxide. Filters from the BIO-X and TETPOR families should be used.
Low levels of sulphur dioxide are still used in some areas to microbiologically stabilize the beer during storage and packaging. It also acts as an oxygen scavenger. However, even at low levels, sulphur dioxide may result in flavor taints. Filtration using PREPOR PP or PREPOR GP filter cartridges reduces the risk of microbiological spoilage of the beer. This can lead to the significant reduction, or elimination of sulphur dioxide. The high removal efficiency of the cartridges provides removal of yeast and significant reduction of bacteria. For high alcohol, very stable beers, these filters can provide a bright, yeast-free product. For beers that are more susceptible to microbiological spoilage, the filters can be used to remove most of the microbiological loading prior to terminal microbiological stabilization using microporous membrane or pasteurization.
Due to their microporous depth characteristics filters also improve the filterability of the beer, protecting downstream membranes from premature blockage due to low levels of colloidal content. In particular, PREPOR PP which can be repeatedly hot water washed, steam sterilized and chemically cleaned can be used as an alternative to sheet filters and provides an effective means of standardizing filterability.
- Can be used in conjunction with crossflow microfiltration to remove yeast.
- Removal of yeast and reduction of bacteria prior to bulk storage or tanker transportation.
- Filterability adjustment and standardization of incoming beer deliveries.
- Colloid reduction or removal.
- Yeast removal and reduction of bacteria prior to microporous membrane filtration.
- Sterilization of gases in contact with the beer.
- Terminal Microbiological Stabilization
- maximizing the packaged microbiological shelf
life
Preparation of beer prior to packaging should be aimed at preserving or enhancing the products' sensory qualities that have developed during boil and maturation. When ready for packaging, any physical instability of the beer should already have been addressed and the only requirement is to ensure that the microbiological shelf life is achieved. Pasteurization is the usual method adopted, either flash pasteurizing the beer on its way to the filling station or by heating the final packaged product. However, even minimal heat treatment will lead to sensory change of the product, which is exacerbated and can become unacceptable if dissolved oxygen content is high.
Terminal microbiological stabilization using membrane microfiltration cartridge filters is carried out immediately prior to packaging. Unlike heat or chemical stabilization, properly selected microfiltration will not impair the organoleptic qualities of the beer.
Membrane retention ratings of 0.65 µm or 0.45 µm are sufficient to remove common beer spoilage organisms. For canned and bottled beer, 0.65 µm should provide the desired stability by a greater number of brewers as it has the ability to remove a wider range of microorganisms, including extraneous non-spoilage species that may be present. The BEVPOR range of polyethersulphone (PES) microfiltration membrane cartridges is ideal for this application. The range also includes 0.8 µm or 1.2 µm pore sizes for instances where yeast content is the only concern, for example in keg beers that only require a shelf life of weeks. However, 0.45µm is increasingly chosen.
All components of the products, especially the PES membrane, have been designed to ensure that their effect on characteristics such as color, foam retention and taste are minimal, avoiding the need for flushing the filter prior to use that some polymers such as nylon or cellulose acetate may require. There are also a number of constructional options to suit a wide range of operational requirements, beer qualities and process conditions.
- Choice of constructional options to cater for various operational requirements and beer qualities.
- Range of pore sizes to remove yeast and common spoilage organisms.
- Minimal adsorption of beer components ensures that desirable characteristics are not affected.
- High loading asymmetrical pore structure with integral prefilter options to maximize service life.
- Wide chemical resistance enables chemical and enzymatic regeneration to extend service life.
- Repeatedly testable enabling easy monitoring for quality assurance and HACCP records.
- Ingredients and Additives
- creating uniform consistency
Ingredients and additives are relatively small volume to the process but important additions are that can be troublesome if not handled correctly.
Liquid sugar additions are common and due to their concentration are usually microbiologically stable. Potential particulate contaminants may be present from storage vessels and pipework, or from upstream processing such as decolorization using granular activated carbon. Clarification filters can be used to remove particulate down to levels of around 5µm. If further color reduction is required, this can be preceded with activated carbon lenticular filter cartridges.
Propylene glycol alginate (PGA) is soluble in beer but can often contain gel clots, particularly after prolonged storage, that are difficult to dissolve. Clarification filters that can be regular cleaned will remove the gel and provide long-term lifetime.
In order to minimize the amount used concentrated flavorings are usually added to bright beer. High concentrated flavorings and fruit juices may require colloidal hazes to be removed prior to addition or they risk impairing the haze of the beer. Lenticular filter cartridges containing diatomaceous earth (DE) or polyvinylpolypyrrolidone (PVPP) deal effectively with many hazes and haze precursors.
Storage of any food ingredients is best conducted in oxygen-free atmosphere to prevent oxidative deterioration and the use of Nitrogen prevents deterioration of the ingredients.
- Color removal from additives.
- Particulate removal for general clarification and fine polishing.
- Removal of haze and haze precursors using adsorptive lenticular filter cartridges.
- Inert atmosphere storage to prevent oxidative deterioration.
- Carbon Dioxide
- ensuring freshness from bulk storage to dispense
Carbon dioxide is widely used throughout the brewery and packaging areas. It is present naturally in the beer as a by-product of fermentation. Its presence can be enhanced using secondary fermentation methods in cask or bottle, or by carbonation using recovered or delivered gas. If recovered carbon dioxide is used, some treatment may be necessary to remove undesirable flavor components from the fermentation process. Delivered carbon dioxide should conform to recognized beverage specifications, but there is still a risk associated with cylinder and line contamination or from the petrochemical source of the gas.
PCO2 and CDP carbon dioxide polishers are designed to give Quality Incident Protection against out of specification CO2. Utilizing a multi-barrier approach both systems are proven to offer effective protection from a wide range of potential contaminants commonly found in gas supplies.
Constructed using a modular design both systems are available in capacities to meet most applications. Small- scale systems are also available for use in retail cellar dispense and laboratory applications.
As well as gaseous contamination, preventing the ingress of extraneous particulate and microorganisms during storage and transportation can be achieved by using filters from the BIO X and TETPOR product ranges.
Any secondary sources of carbon dioxide used to carbonate beer should also be treated to protect against microbiological contamination.
- Added security of CO2 quality.
- Protection against impurities known to result in flavor defects.
- Effective at removing a combination of potential contaminants.
- Easy maintenance, disposable cartridge design.
- Compact design.
- Nitrogen
- flexible options for minimizing dissolved
oxygen
The use of nitrogen in the brewery is increasing. It can be used in many of the applications that carbon dioxide has traditionally been used but has the advantage that it is less soluble and, now, is more readily available than delivered carbon dioxide.
Until recently, nitrogen was only available in delivered form, in bulk or cylinder. Now, a more flexible and economic option is available. MAXIGAS is a modular range of nitrogen generators that produces the nitrogen from compressed atmospheric air. MAXIGAS is able to produce a range of purities up to 99.999% and can be specified to provide nitrogen requirements for a range of applications in the brewery and packaging facilities.
Nitrogen is used to prevent contact of ingredients with air, thereby reducing the potential for oxygen uptake. During bulk storage, the use of sealed tanks means that positive nitrogen pressure can be used, ensuring that volume changes due to temperature fluctuations do not lead to the ingress of air. Nitrogen blanketing of atmospheric tanks is also possible, a small continuous flow ensuring that air cannot diffuse into the headspace through vents and also compensating for volume changes. During emptying, the flow of nitrogen can be increased to fill the head-space and in sealed systems can be used to aid tank to tank transfer. Low oxygen levels will also suppress microbial growth.
Use of filters from the BIO-X and TETPOR families on tank vents and nitrogen inlets will ensure that particulate and microorganisms are removed from the gas streams.
- On-demand nitrogen up to 99.999% purity.
- Modular, space-saving design that can be expanded as requirements increase.
- Low maintenance.
- Removal of particles, aerosols and bacteria from nitrogen distribution lines and tank vents.
- Chilling
- creating the right environment
Low temperature storage is desirable throughout the post-fermentation processes. In addition, specific chilling requirements may be needed:
- To regulate the temperature during fermentation.
- During the layering process.
- During filtration of 'ice' beers.
domnick hunter Hiross has more than 30 years experience in the manufacture of industrial cooling systems. In recent years a wide range of chillers for the food and beverage industry has been introduced. Coupled with a sales and engineering team capable of providing customized solutions to meet individual needs, this provides a dedicated approach to the requirements of brewing applications.
The technology is characterized by a high refrigeration yield for low electrical consumption. Combined with a small footprint this leads to a compact, space-saving and energy efficient solution.
Chillers are available for internal and external installation and are equipped with microprocessor intelligence providing precise control and automatic function.
- Standard and custom designed options provide unrivalled choice.
- Wide range of cooling capacities.
- Minimal space-saving footprint.
- Low energy consumption.
- Water
- clear options, clear results
Water is an essential but expensive commodity. It has many uses in the brewery and the level of treatment required differs according to the source and quality of the incoming water, as well as the application that it is to be used for.
Water for general use will require coarse clarification to remove larger particles. This can be economically achieved using general clarification filters from the PROSPUN or PROPLEAT ranges. At the other extreme the water used for bottle washing or for blending should be sterile to ensure that no extraneous microorganisms are introduced to the beer. The same BEVPOR range of polyethersulphone (PES) membrane filters that is used for beer also suits water sterilization. For intermediate production stages and make-up of CIP solutions, where the water is used to clean and sanitize pipework, bottling equipment and process filters, fine clarification offered by PREPOR GF and PEPLYN range filters are ideal.
Multi-barrier techniques may be used, for example where water for blending requires softening or demineralization. In this case, filter selection is based on the combined performance of the overall treatment process, protecting expensive ion exchange resins and reverse osmosis membranes and trap filtration to prevent shedding of ion exchange resin or carbon from granular treatment processes.
For small to medium dechlorination requirement, treatment using the CARBOFLOW range of activated carbon cartridges may offer more suitable protection than granular beds.
- Wide range of retention ratings provides coarse and fine clarification and sterilizing options.
- Options to suit filtration-only and multi-barrier treatment.
- Dechlorination to prevent formation of flavor taints.
- High mechanical strength and chemical resistance enable washing and regeneration of the filters to increase service life.
- Direct impact on quality assurance and HACCP frameworks.
- Steam
- for general plant and culinary applications
Steam used to sterilize product contact surfaces should be of culinary quality to ensure that it does not contaminate the product with particles or chemicals that could be damaging to the quality of the product or hazardous to the consumer. The water quality used for culinary steam generation is addressed in The Food and Drugs Administration's Code of Federal Regulations. The quality of the water and permitted boiler additives are addressed specifically in the following Code of Federal Regulations:
Water Quality: CFR Title 40 Parts 141,142 and 143
and
Boiler Additives: CFR Title 21 Chapter 1, Section 173.310Other aspects to its treatment are provided in 3-A standard 609-02. This states that pipework and associated equipment should be constructed from 300-series stainless steel and that filters used for particulate removal should be capable of retaining >95% of particles of size 2 micron or larger.
domnick hunter provides a number of steam filtration options for general and culinary use together with a comprehensive guide to their selection.
- Stainless steel housing and filter cartridges for general or culinary use.
- Sintered and pleated fibre filters options provide wide sizing options.
- Jumbo range for high volume applications.
- Comprehensive guide
- Compressed Air
- selecting the ideal management system for your needs
The quality of air required throughout a typical compressed air system can vary. The extensive range of purification equipment available from domnick hunter is ideal for both centralized and decentralized compressed air systems. This allows the user to tailor the quality of air for each specific application, from general purpose ring main protection, through to critical clean dry air (CDA) point of use.
domnick hunter can tailor its range of purification equipment to exactly match system requirements, ensuring both capital and operational costs are kept to a minimum.
To achieve the levels of cleanliness specified by ISO 8573.1 2001 a careful approach to system design, commissioning and operation must be employed.
It is highly recommended that the compressed air is treated prior to entry into the distribution system as well as at each usage point or application.
This approach to system design provides the most cost effective solution to system purification as it not only removes the contamination already in the distribution system, it ensures that only the most critical areas receive air treated to the highest level.
- International system of air quality classification.
- From compressor house to point of application.
- Best criteria for selecting the correct air treatment products.
- See publication 17 400 4765 for detailed information.