A used fermenter is one of the best values in craft brewing — but only if you know what you're looking at. Tanks are simple in concept and unforgiving in the details. This checklist walks through the twelve things worth verifying before you buy a used fermenter, whether you're inspecting in person or reviewing photos from a brewery liquidation.
Structure and shell
- Weld quality — welds should be smooth, continuous, and passivated. Rough or discolored welds are harder to clean and can harbor infection.
- Interior finish — a proper interior polish sheds soil and cleans predictably. Pitting or heavy scratching is a red flag.
- Dish bottom and cone angle — a steep cone (typically 60°) drops yeast and trub cleanly. Check the cone for dents that could trap sediment.
- Shell dents and rounds — minor cosmetic dents are fine; sharp creases near welds are not.
Temperature control
- Glycol jacket coverage — dimple or channel jackets should cover the cone and sidewall. More coverage means tighter temperature control.
- Insulation condition — sagging or water-stained insulation suggests a past jacket leak.
- Jacket pressure test — a jacket that won't hold glycol pressure is an expensive repair. Ask whether it's been tested.
Fittings, safety, and cleaning
- Pressure rating and PRV — confirm the tank is rated for your process (many unitanks carry a ~15 PSI rating) and that the pressure-relief valve is present.
- CIP arm and spray ball — verify clean-in-place hardware is intact so you can actually sanitize the tank.
- Racking arm and valves — check that the racking arm rotates and that butterfly valves seat cleanly.
- Manway gasket — gaskets are cheap, but a warped manway frame is not. Inspect the sealing surface.
- Documentation — provenance, prior service, and pressure-test records turn a gamble into a confident purchase.
Fittings and gaskets are cheap to replace. Welds, jackets, and interior finish are not — weight your inspection accordingly.
Turning the checklist into an offer
Every item above is either a pass, a cheap fix, or a deal-breaker. Cheap fixes — gaskets, valves, a spray ball — should come off your offer price, not off your list of candidates. Deal-breakers like a failed jacket or heavy interior pitting are reasons to walk.
When tanks come from a source that already inspects and documents each one, most of this work is done for you. Browse inspected used fermenters and brewery tanks or reach out through our contact page to ask about a specific tank.