AQUIONICS Regional Sales Manager - Industrial (Eastern US and Latin America) at Halma plc
As you pack your bags and head to the Craft Brewers Conference next week, what’s the burning question on your mind? Let me guess… Can microbial growth in your pretreatment carbon bed affect final product quality? Did I get it right or what! OK, maybe not but did you know that the boiling process of the wort may not be enough to completely eliminate any concerns related to microbial growth and its effect on product quality and consistency? In the same way that the proper yeast for a German Hefeweizen is one that produces plenty of amyl acetate and 4-vinyl guaiacol is the same reason that you want to ensure that unwanted microbes are eliminated (so you can prevent them from producing their undesirable byproducts). And off tastes and aroma aside, microorganisms in the feedwater can also affect the following: 1. Reduce extraction efficiency in the mash 2. Slow fermentation rates 3. Slightly alter the pH in the mash 4. Reduce filterability of the mash (creating more beer haze). Municipal water is not sterile. Microbes are entering the carbon bed. And while the porous nature of carbon makes it fantastic for removing chlorine, it also creates an ideal place for these microorganisms to hide and multiply (see the growth rate in the image below from a carbon bed that had recently been backwashed…with micro numbers pre-UV and post-UV). Regular steam sterilization of the carbon bed can help mitigate this risk (as is common in the pharmaceutical and beverage industries) but…most carbon towers at breweries are not built to handle steam sterilization. Curious if microbial growth in the carbon bed is having a negative impact on your beer quality? Start by taking more regular micro samples between the carbon bed and mash tun and measure for either HPC (heterotrophic pate count) or even ATP to get an idea of the micro load. Have you seen that new, more sensitive ATP test from Kikkoman Biochemifa Company? It’s pretty slick. Anyway…if loads are “high”, perhaps it’s worth addressing this through the use of UV post-carbon, reconsidering your maintenance protocols for the carbon bed, or replacing your carbon (and perhaps investing in a steam sterilizable carbon tower). Interesting in beating this horse to death in person? Come see me at the AFTEK filtration inc booth 1716 at the trade show. #CraftBrewersCon #craftbrewersconference #brewery #beer #beerindustry
