Whether a spare is worth the upfront cost depends on usage pattern and how disruptive running out unexpectedly would actually be.
A spare avoids a mid-event interruption
See our note on CO2 running out before beer does — running out of gas during active use stops serving entirely; having a spare cylinder on hand means switching over rather than pausing an event to source a refill.
Occasional, predictable use may not need a spare
For light, predictable weekend-only use (see our related sizing note), tracking consumption and refilling with reasonable lead time before running out may be entirely adequate without the upfront cost of a second cylinder.
Regular entertaining tips the calculation toward keeping a spare
A household that hosts regularly, where an unexpected mid-event outage would be genuinely disruptive, has a stronger case for the spare’s upfront cost than one with lighter, more predictable, non-time-sensitive usage.
What to do in practice
Track actual usage for the first several refills; if usage is regular and entertaining-driven, a spare cylinder is a reasonable investment against mid-event disruption — for light, predictable use, refilling with lead time is often sufficient.
What we would not do
Suggest every kegerator owner needs a spare cylinder by default — the value of one scales with how disruptive an unexpected outage would actually be for the specific usage pattern.
Last reviewed 25 August 2026