Thomas Soukup, Clarity Water Technologies, Perry Hall, MD, U.S.A.
Thursday, October 12
Imperial Salon B
Microbiological control in pasteurizer water treatment has proven to be an integral component in producing a top-quality package and a clean, fresh-tasting beer. This topic has been the subject of much scrutiny and discussed in numerous Master Brewers publications. The off-spec musty taste that was being experienced in the canned product of several major U.S. breweries was the result of empty can exposure to airborne bioactivity above the pasteurizers. The empty cans were imbued with a musty flavor emanating from the air in the packaging area. The traditional bromine-based biological control the programs employed was reexamined. Summarily, the programs were redesigned to incorporate chlorine in the biological treatment of the pasteurizer. Chlorine is 3 times as volatile as bromine and helped to control microflora activity in the critical vapor zone. The paradox was that the water was being treated in an attempt to control biological activity in the vapor zones! In the cooler zones of the pasteurizer, where volatility is reduced, halogen overfeed to the water was a common occurence. Often 10–15 ppm halogen residual was necessary to provide the requisite vapor phase cleanliness. This practice had some unfortunate consequences: pasteurizer corrosion from excess halogen feed; polypropylene belt degradation, resulting in numerous belt breakage incidents; worker exposure to the high halogen levels causing complaints and potential health issues; high cost for bleach and sodium bromide; increased conductivity and chlorides in the pasteurizer water; and increased ph of pasteurizer water leading to can staining and deposition. I began working with a longtime supplier in an attempt to mitigate this issue. The supplier had been sucessfully impregnating an inert media with a proprietary compound to produce chlorine dioxide at a controlled rate over a 90-day period providing the following benefits: reduced water treatment chemical feed; reduction of biological activity in both the vapor and water phase; reduced corrosion in the pasteurizer; reduced conveyor and belt degradation; improved sanitation on floors and conveyors outside the pasteurizer; reduced boilouts as vapor phase slime was eliminated; ease of feeding; and a safe clean and healthy packaging environment. This novel system only needs attention every 90 days due to the controlled release of the chlorine dioxide at very low levels. The effective chlorine dioxide levels in the air are well below the OSHA guidelines. Treating the air directly has proven to have many benefits well beyond initial expectations. I woud be shocked that if in the next few years this technology is not embraced in all the major breweries.
Tom has been involved in water treatment for 37 years and involved in the brewing industry for the majority of his career. He is a longtime Master Brewers member, presenting numerous papers at conferences and district meetings. He attended the University of Pennsylvania and earned degrees in geology and chemistry. In his former job as manager of brewery services, he traveled extensively in North America. He has designed and implemented water treatment automation chemical feed systems in almost all of the major U.S. breweries, establishing a new paradigm for pasteurizer water treatment. Tom has visited and provided water treatment consultation in every major U.S. brewery. Tom is presently VP of technical sales with Clarity Water Technology based in Congers, New York. He currently resides in Baltimore, Maryland.