Purging keg before filling

[Crinkle]

Bug, how long do you keep the starsan before dumping it??

[Bugeater]

I check the ph now and then and have had no problems with the ph staying good for up to six months. I normally use up 5 gallons quicker than that so I don't know how long it will stay good. This type of shelf life is only good if it is mixed using distilled or RO water and is kept clean. In other words don't use some of it and then pour it back into the keg with the pristine stuff. When mixed with tap water, the carbonates tend to neutralize the ph.

Wayne

[brewinhard]

Always purge your kegs before filling. It just adds that extra piece of mind.

[LordUlrich]

How do you do it? I usually use CO2 to push out the starsan I used to sanitize the keg. I always feel a little like I'm wasting CO2 since that's basically one less keg-worth of beer I'll be able to dispense with that tank of CO2. Maybe I'm using more than I need?

I only run a small amount of star san out and then leave some in the line. Then I dump the rest ( I'm only putting about a gallon or so in the keg and shaking it). Then I run the CO2 for a few seconds and then fill from the bottom. Since the CO2 is heavier, I assume it's falling to the bottom and pushing the O2 up. I know some attach the CO2 to the liquid posts so it fills the CO2 from the bottom, but I go a disconnect stuck doing that once so I don't so it anymore.

I am not sure where this whole heaver so it displaces O2 came from. Stratification of the gasses will only occur if you fill gently from the bottom. And even then it will dissipate relativity quickly. Otherwise how would be breath, all of the o2 would be way up in the air. if you want to purge, run water or starsan then you know it is purged, and then fill without opening the top of the keg, just vent the head-space and fill through the liquid out port.