The Phantom Brewer has seen some brewers in the club use an older technique of keeping a counterflow chiller (CFC) clean by filling the line with sanitizer. TPB has always been deeply troubled by this practice. The copper tubing used in chillers is sensitive to long term acid exposure. Also, many sanitizer solutions become ideal bacterial and mold breeding grounds as they drift from their effective pH range during long storage times. Nope, TPB doesn’t like this one bit.
Instead, TPB would like to recommend that you go the opposite route and store your CFCs bone dry. This will prevent the growth of mold and reduce copper patina. The most effective way to dry your chiller is that trusty bottle of carbon dioxide you use for your kegs. Remove whatever keg adapter you have from the line and press the gas line over the output side of your CFC. Hit the CFC with bursts of CO2 until you’re blowing dry from the line. All done! Remember CO2 is cheap, bad beer is expensive! tpb