3M Separation and Purification Sciences Division Customer Application Brief Filter Press Replacement with Zeta Plus™ Depth Filter Cartridges for Beer Clarification Introduction Filter presses have long been used by breweries in cellar operations to clarify non-pasteurized or draft beer prior to final membrane filtering and packaging. This clarification process is essential to economical membrane filtration in that beer not prepared in this manner will more quickly plug the membrane filters, leading to higher processing costs. The filter press format has been popular for many years since it is generally reliable, and the filter sheets contained in them are relatively inexpensive, commodity items. A filter press is typically composed of a series of stainless steel frames that hold cellulose-based depth filter sheets or pads. Turbid beer is pumped through the filter sheets, which retain undissolved solids, yeast, most bacteria, hazes, and other turbidity causing components. However, as breweries modernize and review their operations, with focus on improvements in efficiency and methods of sanitation when preparing beer for bottling, many upgrade the clarification process to include more cost effective, environmentally sealed cartridge filters in place of the filter press. Deficiencies in the filter press design are well known and include: leakage of beer, exposure of the filter media and beer to contaminants in the environment, oxygen pickup, high labor and maintenance costs, and high capital costs for the equipment. This Application Brief describes the benefits of an alternative method of beer clarification that employs totally enclosed Zeta Plus depth filter cartridges. Those benefits include: • Zero leakage of beer • Low maintenance • Reduced labor • Reduced disposal • Fewer change outs • Minimal floor space • Decreased capital costs • Reduced energy needs The Process While beer filtration processes vary according to beer style and preferences of the brewer, the schematic shown in Figure 1 is meant to serve as a generic process. Primary Separation of yeast and undissolved solids is usually achieved by centrifugation and a diatomaceous earth (kieselguhr) filter. The use of fining agents and enzymes, if acceptable, assist in this operation. Zeta Plus™ depth filters are available in 8”, 12”, and 16” diameter cartridges. Continued clarification by removal of remaining yeast, most bacteria, and haze colloids is then achieved by a filter press or by the Zeta Plus cartridge system. While these operations typically take place in the cellar, final membrane filtration is usually performed in the bottling room. Difficulties Associated with Filter Press Operation The following difficulties have been expressed by many breweries regarding the operation and main tenance o

Filter Press Replacement with Zeta Plus™ Depth Filter Cartridges for Beer Clarification Sterile tank vent O2 removal Filtered water Fermentation tank Mash mixer Brewing kettle Pushing Water O2 removal Sterile tank vent Gas Control Blending Water Non-pasteurized beer Final filter Bright beer tank Trap filter Figure 1 – Generic Non-Pasteurized Beer Process Labour As anyone who has changed a filter press can attest, the labor required to properly unload, clean, repack, and ready a filter press for the next filter run is substantial. Estimates range from 3 man-hours for smaller presses to up to 8...

Filter Press Replacement with Zeta Plus™ Depth Filter Cartridges for Beer Clarification Capital Costs A modern, all stainless steel filter press comes with a significant capital cost. Additional hardware for automation and hydraulics can add further to this cost. The used filter press market can offer a reduction in this capital cost, but usually at the expense of increased maintenance, and replacement parts costs down the line. Maintenance With a number of moving parts, o-rings, and gaskets, filter presses require considerable attention to routine maintenance for proper operation. For instance,...

Filter Press Replacement with Zeta Plus™ Depth Filter Cartridges for Beer Clarification Fewer Change-outs Since Zeta Plus cartridges are installed in a totally enclosed filter housing and not exposed to the atmosphere, the cartridges can continue to be used until they reach a maximum differential pressure (2.4 bar), indicating that their useful life has been achieved. Depending on the nature of the beer and how well it has been prepared prior to filtration (racking, fining, D.E. filtration), a single set of cartridges can be used for weeks prior to plugging, unlike the filter press, which requires...

Filter Press Replacement with Zeta Plus™ Depth Filter Cartridges for Beer Clarification Reduced Energy The compact nature of the Zeta Plus cartridge and housing design results in much faster sanitation cycles, greatly reducing energy costs. Since the 3M series filter housing design has less stainless steel than a filter press, it can be brought up to tempe rature much more quickly and reliably. Additionally, the sanitary design of the 3M series filter housing eliminates dead-legs and other hard to clean areas common in a filter press that are difficult to sanitize correctly. Conclusion and Summary...

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