Glossary
Line cleaning
Regularly flushing the tubing between container and tap with cleaning solution to remove yeast, bacteria and beer stone.
Dirty lines are among the most common causes of bad beer in a pub, and the fault is entirely invisible to the customer — beer that tastes sour, vinegary or musty from a well-regarded brewery is far more often a line problem than a brewery problem.
Trade practice is generally weekly for cask and keg lines.
Related
- Cellar conditioning — The wider discipline it belongs to.
More vocabulary
Beer-clean glass · Brewer’s barrel · Cask · Cellar conditioning · Crowler · Draught · Firkin · Growler · Imperial pint · Keg
See every term on the glossary index.
Last reviewed 2026-08-16.
Evidence
What BeerHQ knows about this, and how. Every statement carries the state of the evidence behind it rather than being presented flatly as fact.
Cleaning to a schedule is necessary and is not by itself sufficient. Sampling of retail draft systems found that routine line cleaning did not suppress spoilage: biofilms persisted through it and re-established the spoilage community, which is why line problems recur rather than being solved once.
Checked against the source
Source: Bose et al., "Microbial Communities in Retail Draft Beers and the Biofilms They Produce" (2021), discussion and Importance (Microbiol Spectr 9(3):e01404-21)