Purging a corny keg

[Cantina De Jefe]

Apart from the side issue of the gas "layering" myth, I must admit there seems to be quite a bit of opinion regarding the simple task of purging the small bit of space in a full keg.... It's really not that complicated.

It really comes down to what style, how long you intend to set it down for, and how anal or lazy/cheap you want to be. My beer always tastes best at the end of the 2nd keg anyways. If a few thousand ppm o2 was so detrimental i would be tasting skunk-a-lotta-piss-on-my-wet-cardboard ale. I mean someday i would like to do spunding and closed transfers but for now i dont want to increase my usage by 1/3. I already had 1 tank leak out this year as it is.

 

[Carolina_Matt]

How old do you need to keep a keg before you notice a downturn due to oxygen? I haven't really worried about oxygen exposure, but maybe I should.

When I keg, I take the top completely off of the fermentation bucket during the process, so it's exposed to oxygen. I rack to a keg, which had been sprayed with Star San. When I'm done, I put on the lid, add ~30 psi of CO2, then leave it for a couple days. I purged a few kegs after adding CO2, but there have been at least a dozen kegs where I didn't purge at all. So I guess there's some oxygen in the headspace, but I haven't really noticed any skunked beers after the keg has been sitting for 1-2 months.

 

[beernutz]

How old do you need to keep a keg before you notice a downturn due to oxygen? I haven't really worried about oxygen exposure, but maybe I should.

When I keg, I take the top completely off of the fermentation bucket during the process, so it's exposed to oxygen. I rack to a keg, which had been sprayed with Star San. When I'm done, I put on the lid, add ~30 psi of CO2, then leave it for a couple days. I purged a few kegs after adding CO2, but there have been at least a dozen kegs where I didn't purge at all. So I guess there's some oxygen in the headspace, but I haven't really noticed any skunked beers after the keg has been sitting for 1-2 months.

I believe skunking is caused by exposure to light, not oxygen.

 

[ApolloSimcoe]

Actually the atmosphere is stratified into two main layers; heterogeneous and homogeneous. I watched the video that was attached. Clearly there are two layers and the narrator states that "over time" and after 1/2 hour the layers have combined. So clearly layers are formed, isn't it just a question of how long the CO2 and O2 layers last and the environment that the gasses are in? For home brewing purposes let's say the time is similar for O2 and CO2 it doesn't take 1/2 to rack or transfer so isn't it possible that there are some benefits to the blanket theory?

 

[TallDan]

Actually the atmosphere is stratified into two main layers; heterogeneous and homogeneous. I watched the video that was attached. Clearly there are two layers and the narrator states that "over time" and after 1/2 hour the layers have combined. So clearly layers are formed, isn't it just a question of how long the CO2 and O2 layers last and the environment that the gasses are in? For home brewing purposes let's say the time is similar for O2 and CO2 it doesn't take 1/2 to rack or transfer so isn't it possible that there are some benefits to the blanket theory?

In the video, the layers are formed artificially, and the gasses are kept as still as possible to illustrate the point.

The amount of time is going to depend on the difference in density of the gasses and any turbulence in the air. When racking, there is going to be a fair amount of turbulence as air is being pulled into the fermenter as the beer is drained, and it's being pushed out as beer is filling the keg.

Really it's a question of "good enough". Some people don't purge their kegs at all, don't even rack carefully, and that's good enough for them. Some are very concerned with "LODO" and go to what I would consider extreme measures to avoid any possible oxygen exposure. I'm somewhere in the middle.

 

[ApolloSimcoe]

I'm in the middle as well. I'm here to learn, hopefully pick up a tid-bit of knowledge.

 

[matridium]

funny that keg purging is just as polarizing as politics and the Patriots NFL

 

[ApolloSimcoe]

Nothing better

 

[jcubit]

My corny has a relief valve in the center of the cover. I fill and add co2 then pull the valve three times. Wait about a minute pull three more times. Let it sit for three days in the kegerator at 38 degrees. Plug in the beer line pull the tap three times quickly and pour away.