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Carbonating in a Unitank


James Broadbent — Wakefield, England asks,

I’ve been brewing now for around 2 years and always bottled the beer out of my plastic buckets. Recently, I stepped my game up a bit and plunged into the realms of Ss Brewtech’s 7 gallon (26.5 L) Chronical. Great bits of kit, really impressed. So, I now have a unitank and a glycol chiller. My question is how do I go about carbonation using the unitank and carbonation stone?

Can’t seem to find an awful lot online regarding the actual method and how long to carbonate. I’ve just done a trial on a lager that I ruined due to leaving it on the yeast for too long so didn’t mind over-carbonating or  wasting it. My steps were as follows:

• Temperature set to 3 °C (37 °F)
• Crank the CO2 pressure up to 20 psi (138 kPa) and left it for approximately 1 hour
• Being scared of over-carbonating, reduced the pressure down to desired 10 psi (69 kPa) to give around the 2.4 mark, and left it for a few days in the unitank at this pressure.

Came back to it at the weekend and it felt under-carbonated. Any advice on this? I like doing my research and would like a tried and tested method using a carbonation stone.

There a few ways to go about carbonating beer using a stone, and I think your approach is sound, but needs a few changes. I will review the method that has worked
Response by Ashton Lewis.