Caustic (sodium hydroxide, NaOH, and potassium hydroxide, KOH) cleaners are typically used to clean draught lines (AKA tap lines or beer lines), with acid cleaning taking a back seat and only used as needed to tackle calcium oxalate (beer stone) issues. Acid cleaning does not remove biofilm as readily as caustic cleaning, but acid cleaning is recommended for beerstone removal on a quarterly basis.
The Brewers Association recently published the Fourth Edition of the Draught Beer Quality Manual (DBQM) and can be found online here. The DBQM recommends cleaning beer lines with caustic every 14 days to keep the lines in good shape. For most beers, this works just fine. But what happens when a non-standard beer is put on a draught line and then ends-up flavoring a different and subsequent beer put on the same line long after the non-standard beer is pulled?
How to Prevent the Old Beer’s Flavor When the Beer Line is Changed
With the myriad of mixed culture, fruited and flavored beers on the market these days, certain beers can taint the draught line and cause off-flavors after they are pulled from rotation and a new and different beer is served on the same line. This situation can create customer complaints and a loss of yield. So, what is the best way to clean the tainted line, so they do not flavor other beers put on the line?
The following method has worked well to remove fruit and other flavors from tainted draught lines:
- Clean with 1 oz. of Acid Brite #2 per gallon of warm water for 15-30 minutes.
- Clean with 1 oz. of Cell-R-Mastr per gallon of warm water for 15-30 minutes.
- Finally, use a 1 oz. of activated Dioxy-Chlor solution per 5 gallons of water for 15-30 minutes.
- Rinse thoroughly and then put the beer on.
This method works well to bring the line back to a neutral flavor state. The next time a flavored beer leaves a lingering reminder after it is pulled, try cleaning it this way. Unless it is a root beer line, this process should work effectively!