Proper Filtration Finds the Sweet Spot Between Art and Science

By: Gerald Dlubala

When the correct brewing process is paired with time and gravity, the result will generally be a great brew. When a brewer speeds up that process, corners get cut, and compensation has to occur. Proper filtration methods are one way to do this, but the methods depend not only on the type of beer brewed but how and when that beer is consumed. Brewery filtration is a carefully constructed combination of art and science that, when done correctly, results in a beer with all the intended flavor and aromas.

Process Should Fit Application: Aftek Filtration Technologies

  “Consistency with stability is the name of the game,” said Jim Russell, regional sales manager of Aftek Filtration Technologies, a provider of filtration systems and processes for many industries, including the craft beverage market. “Too many try to fit a certain process into an established application when they should be looking at the application first and then finding the right process to fit that application. With the proper filtration process, you’ll have usability with consistent and repeatable results without the chance of biological instability. If you’re a brewpub that mainly sold crowlers or used an in-house draft service, a different level of filtration may be necessary if, due to the ongoing COVID situation, you’re now canning or bottling most of your beer and getting it to market using a distributor. Packaging their beer has become one of those decisions forced upon breweries, with more now using mobile canning or co-packers to offer to-go products and widen their distribution. More attention has to be given to shelf life, distribution methods and spoilage awareness. As a brewer, you want your finished product to resemble your original brewpub pour and retain as much flavor as possible without allowing any sludge, unwanted haziness or off-taste entering the picture.”

  Russell told Beverage Master Magazine that a brewer must get started with an initial, informed filtration choice to set a quality benchmark, then make adjustments based on the results.

  “We at Aftek go in, assess the needs and then find the right filtration to fit the product needs with minimal effects,” said Russell. “Some filtration naturally adds taste-affecting properties to your beer, and we want to minimize that. Some of those properties are recoverable through adjustments and additional filtration, but upfront awareness is the key. You can save from 25 to 50% of your flavor and aromas by simply making the proper filtration choice. For example, Diatomaceous Earth filters are economical and efficient, but they can be aroma and flavor scavengers, ultimately changing a beer’s character.  Pad filters can be backwashed, regenerated and reused, but if there is any remaining minerality in the pads, the chance of biological contamination increases. Proper filtration starts with awareness of detail and remaining consistent in using quality filtration media rather than the cheapest, which can be wrongly classified. This consistent and constant attention to detail is the only way to make progress on and obtain the ultimate goal of balancing consistent flavor profiles with optimal shelf-life.”

  Types of filtration include depth and surface. Depth filtration is a primary form and can be the only type of filtration used for many smaller craft brewers. Depth filtration includes frame, plate and screen filters that trap particles for removal. Surface filtration traps smaller particles on the surface of the material while allowing clarified fluid to pass through. Lenticular filters work similar to plate and frame filters, but the modules are enclosed and purged with CO2, decreasing biological instability and oxygen exposure. Regular physical filtration only gets particles that are in suspension. Russell suggests cartridge and microfiltration for finishing and fine-tuning the beer just before packaging.

  Russell told Beverage Master Magazine that seltzers present a whole different situation because of regulations. Malt-based products must retain a minimal amount of malt percentages. Seltzer makers want to create a malt base with as light of a concentration as possible before flavor blending, and carbon absorption filters can neutralize the base. Russell said there are other products and ways to filter seltzers, but no matter the choice, brewers should neutralize before blending. Like beer, the end goal is drinkability with no aftertaste, which is unachievable if using improper filtration methods or processes.

  “The bottom line is that you want to preserve drinkability and bring your product to the consumer with no issues,” said Russell. “Within your brewery and specific situation, you have to consider capital costs versus consumable costs to help determine the type of filtration equipment needed and to make sure you don’t under or oversize your filtration systems.”

  Aftek Filtration Systems meets all filtration needs from start to finish, from incoming water supply to outgoing wastewater treatment. They work by building a comfort level with their clients, including warranties on their products and available inventories of filtration media to help keep costs down while producing the desired continuity throughout the entire brewing process.

  “We touch base and sit down with our clients every few months to discuss concerns relating to business growth and future needs, or to just see how things are going,” said Russell. “We educate the brewer when needed and cover available options when they are ready for the next level of filtration, for example, switching from pads to centrifuges.”

  Centrifuge technology has traditionally been out of reach for the craft brewer, but it is becoming more affordable and attractive. Brewers see the cost-effectiveness and user-friendliness along with the reports of higher yields, better flavor and aromas, and increased shelf life. Additionally, unlike filter pads, they won’t become clogged or bogged down, causing downtime. Instead, reports show centrifuges save time, recover man-hours, increase run times, and streamline the tank turnover and brewing process.

  “We’ve seen the size of the entry-level centrifuges drop into the $100,000 range, making them a little more affordable,” said Russell. “I see more and more brewers in the 20,000-30,000-barrel range getting into centrifuges, but making the jump has to be based on an informed decision. It’s one of the topics when discussing return on investment, including consumable savings, labor, quality, product savings versus loss and dissolved oxygen uptake.

  “The biggest bit of advice I can give to brewers is to put thought into and select the proper professionals to work with and advise you, and then get the proper equipment to reach your goals and specifications. Whether you’re talking about filtering through chemistry, pads or labor only, the whole process is a flavor versus filtration issue. There is no magic wand that can do it all. Talk to your business neighbors and see what they use and if they’re happy with it. Have they used it for at least a year? What about the service aspect? Filtration in the brewing process is finding what works the best at the best cost while retaining consistent results, preferred shelf life and optimal drinkability.”

Reliable Utilities Filtration for Reliable Outcomes: Donaldson Filtration Solutions

  “Admittedly, in any brewery, there are numerous points in the brewing and packaging process where filtration can be critical,” said Scott Grimes, technical training manager for Donaldson Filtration Solutions, a global provider of filtration solutions for food and beverage processing.  “By starting with proper filtration for your primary utilities like air, water, steam and gases, a brewery is on track to not only produce a great product but just as important, to be compliant under FDA and industry standards. Those standards include important topics including hygienic design, allergen-free environment, integrity testing, and BSE/TCE statements certifying that products used are safe and free from harmful materials.

  “For these reasons alone, breweries should be working with experts to assess and size their filtration needs,” said Grimes. “Product filtration, in its simplest form, is simply keeping the undesired brewing remnants out of your beer, especially when producing bright or lighter beers. You do that by understanding a brewery’s demands, identifying where the utilities come in contact with the process or beverage itself, and then setting up the right filtration to help mitigate any possible micro-contamination. Trap filters, for example, are commonly used as post-finning agent filters because they are very efficient at catching the remnants of agents like Diatomaceous Earth from entering the bright tank. They also guard against any powdery remnants traveling downstream in the brewing process. Trap filters are regenerative, inexpensive, long-lasting, and ensure stable, contaminant-free beer that retains its characteristics and flavor profile.”

  “The utilities are an important place to start in implementing the right filtration for any brewer, no matter the size or output. Sterile air, free of any oils and moisture, is used in everything from wort aeration through the finished product packaging. It’s critical to effective and consistent yeast propagation and the proper facilitation of the fermentation process. Particulate-free, quality water is equally critical for use as an ingredient, in steam applications, and for process water,” Grimes said. “Feedwater can contain contaminants like pipe scale, sludge, organic matter, sediment or other suspended solids. Clean and sterile culinary steam is used in multiple situations, including steam distribution services necessary to retain heating efficiency in boiler systems, cleaning and sanitizing equipment in between batches, and sterilizing kegs before reusing or filling. Protecting your investment means making sure that your finished product is packaged and distributed in clean, sterile vessels.”

  The same holds for gases and their filtration needs. When using CO2 to push out a product, clean and sterilize processing lines, deliver CO2 for pipe aeration systems or purge cans or bottles before filling, sterile CO2 ensures the finished product is delivered in clean, sterile containers.

  Grimes told Beverage Master Magazine that presently, more than anything, market shifts like the recent move to widespread seltzer production are what affects filtration needs. Filtration processes respond to increased seltzer production by moving towards flavor enhancement protection balanced with shelf-life expectations of anywhere between three weeks to three months. Because more products are packaged for distribution, held in warehouses and delivered under less than ideal conditions, seltzer producers must filter out spoiling agents adversely affected by temperature fluctuations. Cold stabilization, an alternative to pasteurization, helps reduce the carbon footprint and improve shelf life without sacrificing the product’s sensory qualities.

  “Brewers can help themselves by performing regular and preventative maintenance on any equipment that is filtration related,” said Grimes. “You should always adhere to a preventative maintenance schedule following best practices and recommendations by the equipment manufacturer. For compressed air, it’s usually on a six to 12-month schedule. Steam filtration should be inspected and cleaned every 12 months or as needed. Product filtration is affected by the media used and its ability to keep spoiling organisms away from the yeast pad and be successfully regenerated. Adhering to a strict regeneration policy and using properly sized equipment, quality filter media can last months, saving money and time. When filtration systems are sized properly and maintained according to schedule, they all work in conjunction with one another along the brewing process path to ensure process integrity and produce the beer that the brewer intended.”

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