I got a SS Brewtech Unitank a little less than a year ago and keep thinking about the potential for oxygen ingress when opening the butterfly valve. I am thinking specifically about the racking port. For instance, I use a 1.5 TC to 3/16 barb to transfer to kegs. There will be air in the transfer line and an air pocket on the outside of the butterfly valve as you open it. Unless this air is pushed out very quickly, there is potential for an air bubble to be trapped between the butterfly valve and the transfer tube, and also potential for air to flow back into the fermenter. I was wondering if anyone has found a way to look at what's happening during valve opening and or looked at oxygen pickup associated with this?
Oxidation and butterfly valves?
- Thread starter maxr
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Golddiggie
Well-Known Member
If you're transferring the beer out, the flow should prevent any gas from going into the fermenter/beer. Even less chance if you're doing a closed transfer/CO2 push.
If you're really concerned about this, Run the line to a 'sacrificial' keg to get the line filled and push any gas out of the line. Post transfer into the target keg (if you have two empty kegs during transfer day) you can dump out what went into the first one.
Of course, this might not be a real issue if you're doing a closed transfer into a target keg that was purged with CO2 before you started. Any potentially harmful 'air' would get forced to the top of the keg and removed when you do a post transfer CO2 purge of the keg.
If you're really concerned about this, Run the line to a 'sacrificial' keg to get the line filled and push any gas out of the line. Post transfer into the target keg (if you have two empty kegs during transfer day) you can dump out what went into the first one.
Of course, this might not be a real issue if you're doing a closed transfer into a target keg that was purged with CO2 before you started. Any potentially harmful 'air' would get forced to the top of the keg and removed when you do a post transfer CO2 purge of the keg.
I attach a male ball lock post to 1/4 barb adapter to the ball lock quick disconnect so that gas is pushed out quickly as the valve is opened, and I generally spund and apply CO2 so yes, there is a few psi pushing the beer out. I'm still not convinced that the air all gets purged from the line. It might be interesting to do a test with an inline sight glass and/or DO meter but I don't have either.
To avoid air pockets in the racking port I attach a male ball lock post to TC adapter to it before filling the fermenter and leave the butterfly valve open all the time. This way the valve is filled with fermenting wort and there is no air trapped anywhere.
When I perform a closed traslfer to a purged keg I attach the transfer line to the fermenter first and then let out a small amount of beer to push as much of the air as possible out of the line. I also keep the line as short as possible (about 4-5 inches) to minimize volume and surface area. The beer is fully carbed (I spund) so pressure in the fermenter is quite high and the beer gets pushed out rather forcefully.
When I perform a closed traslfer to a purged keg I attach the transfer line to the fermenter first and then let out a small amount of beer to push as much of the air as possible out of the line. I also keep the line as short as possible (about 4-5 inches) to minimize volume and surface area. The beer is fully carbed (I spund) so pressure in the fermenter is quite high and the beer gets pushed out rather forcefully.
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