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When I moved from bottling to kegging, the upfront cost felt steep, a Cornelius keg, a CO2 cylinder, a regulator, and a faucet add up to $150–250 depending on where you shop. What I didn’t realize was how much of that cost could be cut by buying used equipment and being selective about where each dollar went. Four years later I have a six-tap keezer built almost entirely from used kegs and second-hand CO2 equipment, and the total investment was less than buying four new kegs at retail. Here’s where to find affordable kegs and what to look for when buying used.
New vs. used Cornelius kegs
New Cornelius kegs cost $80–120 depending on size and supplier. Used Cornelius kegs (ball lock or pin lock) cost $30–60 on the used market and perform identically to new kegs after a cleaning and o-ring replacement. The used keg market is well-established, these kegs were originally used by the soda industry and are extremely durable. A keg with a dent or surface rust on the exterior is typically fine; the interior stainless is what matters for beer contact. Any used keg should receive a full disassembly, PBW cleaning, and o-ring replacement before first use. An o-ring kit for a Cornelius keg costs $3–5 and eliminates leak issues from aged seals.
Where to find affordable kegs
- Craigslist and Facebook Marketplace: The best source for used kegs at the lowest prices. Search “Cornelius keg,” “corny keg,” and “ball lock keg.” Prices of $25–50 for a used keg in working condition are common. Inspect in person before buying, check that the lid o-ring is present, the posts aren’t stripped, and the interior isn’t badly scratched or corroded.
- eBay: Wider selection than local listings but shipping adds $15–25 for a single keg. Best for finding specific sizes (2.5 gallon, 3 gallon) not commonly available locally.
- Homebrew club equipment swaps: Members frequently sell kegs, CO2 equipment, and fermenters at homebrew club meetings at below-market prices. Join a local homebrew club if you aren’t already, the used equipment market within the community is excellent.
- MoreBeer and Adventures in Homebrewing: Sell reconditioned used kegs ($50–65) that have been inspected, cleaned, and resealed. More expensive than buying directly from a private seller but guaranteed to be in working condition.
Ball lock vs. pin lock kegs
Ball lock kegs (Cornelius) use quick-disconnect ball lock posts, gas and liquid posts are the same diameter and are distinguished by color or thread direction. Pin lock kegs (Firestone, Spartanburg) use a pin-lock fitting with different numbers of pins for gas and liquid posts. Ball lock kegs are more common in the homebrew market and have wider accessory availability. Pin lock kegs are often slightly cheaper on the used market. If you’re starting from scratch, choose ball lock for better parts availability. If you find a deal on pin lock kegs, they work just as well, just buy the correct pin lock disconnects.
Budget CO2 equipment
- CO2 cylinders: A 5 lb aluminum CO2 cylinder ($60–80 new) is the standard for a 2–4 tap home setup. Used cylinders in hydrostatic test date are available for $20–40 at homebrew shops and online. Cylinders require hydrostatic testing every 5 years, factor this cost ($15–20) into buying an older used cylinder.
- Regulators: A dual-gauge CO2 regulator ($30–50 for a basic Taprite or Micromatic) is sufficient for serving one or two kegs. Dual-gauge means you see both delivery pressure (what the keg receives) and tank pressure (how much CO2 remains). Don’t buy the cheapest single-gauge regulators, they don’t show tank pressure and you run out of CO2 unexpectedly mid-keg.
Common Questions
How many batches does a 5 lb CO2 cylinder serve?
A 5 lb CO2 cylinder carbonates and serves approximately 10–15 five-gallon kegs under normal conditions (10–12 PSI serving pressure, minimal purging). Real-world usage varies: if you purge kegs heavily during filling, use high pressure to push transfers, or serve at high carbonation levels, you’ll use more gas per keg. The tank pressure gauge gives you a direct reading of remaining CO2, most 5 lb cylinders hold about 1400 PSI when full and deliver gas consistently until pressure drops below 200 PSI, at which point output pressure becomes unreliable. Get the cylinder refilled when the gauge drops to 400–500 PSI rather than waiting for it to run out mid-serve.
