Force Carbonation Root Beer After Taste

I have a 20lbs CO2 Tank that I use for force carbonation and beer service. The current setup is a dual regulator and a 2way CO2 distribution bars which feeds two soda kegs.

A few months back, I force carbonated a root beer for my daughter to enjoy. I now have a dedicated tap and soda keg for this purpose. The CO2 remained connected to the rootbeer soda keg for several months until the keg was fo emptied. During this time frame, the other leg of the CO2 remained unused.

I recently force carbonated two separate beers and noticed an odd off flavor in both the beers. I haven't changed any of my cleaning processes and have been brewing for over 7 years.

I am of the opinion that the root beer flavor caused an off-flavor inside my gas lines. Has anyone else experienced this? I am going to replace all of my gas lines.

Both of these beers tasted very clean prior to force carbonation and didn't have the off flavor until this process.

How sure are you? Does it definitely taste like Root Beer or is it more of a general "wierd" flavor? You might have something growing in the line, what with all that sugar in the RB and no alcohol to help kill baddies.

It certainly could be something growing inside the line. It seems to have a "hint" of rootbeer odor but could be something causing a bug as well. Thanks for the reply