Cicerone Certified Beer Server Practice Test

If draft lines are not cleaned regularly, the most likely flavor to develop is butter. This is because the presence of residual yeast and bacteria in the lines can lead to the formation of diacetyl, a compound that emits a buttery aroma and flavor. Options A, C, and D are not typically associated with dirty draft lines. Banana flavor can develop from a specific type of yeast used in certain beers, but it would not be the most likely flavor to develop from unclean lines. Paper flavor is often associated with oxidized beer, which can happen from poor storage or old kegs, but not necessarily from dirty lines. And skunk flavor is typically a result of light exposure, not unclean lines.