What is essential to confirm regarding the beer keg while troubleshooting?

Confirming that the beer keg needs to be full is essential while troubleshooting because an empty or low keg can lead to operational issues such as inconsistent or interrupted beer flow. When a keg runs low, it may cause air to be drawn into the system, which can lead to foaming, undesirable flavors, and a poor drinking experience. Ensuring that the keg is adequately filled allows for proper pressure maintenance and consistent dispensing. This is a fundamental aspect to check, as it directly affects the quality and delivery of the beer.

While other factors like temperature and beer style may influence the serving characteristics, verifying that a keg is full is the most immediate concern that affects the functionality of the dispensing system.