Purge headspace of pre purged keg

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Alf34

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Hello

As many, I currently do a low oxygen transfer where I purge my keg pushing out all the star san, I then connect the tap of the fermenter to the liquid disconnect, slighly open the airlock to allow air flow, open the tap and let gravity do the rest of the work.

Once I have finished transfering all the beer, should I also purge the headspace with CO2? It is necessary if the keg has already been pre-purged?

If recommended, and since I carbonate and serve having the keg lying on it's side, should I purge the headspace when the keg is lying down or standing? The volume of headspace is obviously not the same although I am not sure it makes a difference.

Thanks!
 
I always flush the headspace after filling purged kegs. Might be unnecessary, but it's trivial to do, and as long as the CO2 line is purged first it can't hurt...

Cheers!
 
I always flush the headspace after filling purged kegs. Might be unnecessary, but it's trivial to do, and as long as the CO2 line is purged first it can't hurt...

Cheers!
Same. My method when I don't use gelatin or dry hop in the keg is to fill the keg with sanitizer, use CO2 to remove it all (also removing all oxygen in the process and replacing it with CO2), then close-transfer the beer into the keg. Afterwards, I hook up the CO2, set it to the desired pressure, then purge the headspace several times. Sometimes I'll come back a few hours later and purge the headspace again. When I add gelatin and/or dry hop, I basically do the same thing, but just add them after the sanitizer is gone, then re-purge the entire keg of oxygen before transferring the beer.

Like Trippr says, while it's probably unnecessary, it uses very little CO2, is super easy and fast to do, and gives peace of mind. I've never tasted anything remotely attributable to oxidization (though admittedly I do 3-gallon batches and go through them in about 1 to 1.5 months), so I find the method pretty efficient.
 
If recommended, and since I carbonate and serve having the keg lying on it's side, should I purge the headspace when the keg is lying down or standing? The volume of headspace is obviously not the same although I am not sure it makes a difference.
The volume of headspace doesn't change when you put the keg on its side. The surface area of the beer exposed to the headspace might change, and that might affect the carbonation rate, but it won't affect the amount of residual oxygen.

I don't worry about purging the headspace when I do a closed loop transfer with everything (including the jumper lines) properly purged. But I don't open the airlock on the fermenter to start the flow; I push CO2 through a gas post and QD to do that. It's a pretty simple modification (and it works on buckets too).
 
I also never open the keg PRV, instead I snap on a gas QD with tubing dunked in a small bucket of water.
But I still flush the head space in the end...

Cheers!
 
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