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Purging With Co2 for the First Time

Hi,

I just finished my first all grain batch a little over a week ago. (IPA OG 1.052 FG 1.010).

I just dropped in a set of dry hops yesterday and want to let that sit for 7 days then rack to a corny keg, purge, let sit for 7 days, force carbonate.

My questions are.

  1. Is it a good idea to purge, let sit, then force carb after 7 more days or will that not make a difference?

  2. How much PSI do I use to purge the keg?

Thanks!

I purge the keg first, on the ball lock type,by switching the posts so it’s filled thru the dip tube. With the pressure relief valve open for about 1 min. Then fill the keg, make sure you switch the posts back, and purge the head space for about 1 min. I turn down the pressure a little when purging and hit it with 30 psi to set the lid. Then check for leaks, put it in the fridge and hook up to serving pressure the next day. It usually takes 2 weeks and it’s ready. There is no need for it to set after dry hop is done, if the beer was finished and you have the hop aroma you like get it on the co2. These high hopped styles are best fresh.

I agree with all of this except the 2 week part. When you hook up your gas leave it set to 30psi for 24hrs. Then release pressure and drop it down to 20psi for another 24hrs. Then release pressure and down to 10psi for 24hrs. At this point you can then start tasting and dialing in the pressure. You may need to leave it at 10psi for another day or maybe turn it down and purge a little CO2, but this should get you very close to where you want to be in only 3 days. It will usually take me another day or two to really get it perfect, but I can easily be drinking well carbed beer in 3 days after filling the keg.

  1. I flush the keg with gas

  2. I runoff from fermentor with low pressure CO2 on the headspace with the fluid tube feeding the bottom of the keg.(Accomplished not by messing with the flow gauge/reg at all. I just use the shutoff valve post regulator to cut the flow down some. Bottom line is I never want to alter the regulator setting unless I really need to as my entire system has been at equilibrium for close to 15 years and I don’t want any surprises at this stage of the game.)

  3. After filled, the keg is purged a few times and put in the beer fridge. ( I use the regular serving PSI of 12 that my system requires and never had a lid leak or other…) ITs good to spray the lid/ posts etc… with starsan to check for gas leaks before putting behind closed doors. Typically I leave the 12 PSI hooked up for 15 minutes or so after a few pulls on the PRV to purge while finishing cleanup and the lid is sprayed right after the purging to show any problems with the tank hooked up, then when unhooked both posts are sprayed to indicate if a post/poppet is going to cause issue. I have never had an “accident” due to this check on each and every keg fill. I have seen plenty of horror stories though and that continues to reinforce this practice.

  4. Yes, I leave a few days(usually 2) for any remaining yeast/hop sediment to drop after transfer and then apply the gas. In the past when I was in a rush to apply gas right away I found it kept yeast etc… in suspension for the life of those kegs and drastically altered the flavor and clarity I was seeking.

  5. Right around 2 weeks then and they are ready to tap as I don’t mess with changing pressures as mentioned above and leave at normal serving pressure all the time.

[quote=“ITsPossible”]1. I flush the keg with gas

  1. I runoff from fermentor with low pressure CO2 on the headspace with the fluid tube feeding the bottom of the keg.(Accomplished not by messing with the flow gauge/reg at all. I just use the shutoff valve post regulator to cut the flow down some. Bottom line is I never want to alter the regulator setting unless I really need to as my entire system has been at equilibrium for close to 15 years and I don’t want any surprises at this stage of the game.)

  2. After filled, the keg is purged a few times and put in the beer fridge. ( I use the regular serving PSI of 12 that my system requires and never had a lid leak or other…) ITs good to spray the lid/ posts etc… with starsan to check for gas leaks before putting behind closed doors. Typically I leave the 12 PSI hooked up for 15 minutes or so after a few pulls on the PRV to purge while finishing cleanup and the lid is sprayed right after the purging to show any problems with the tank hooked up, then when unhooked both posts are sprayed to indicate if a post/poppet is going to cause issue. I have never had an “accident” due to this check on each and every keg fill. I have seen plenty of horror stories though and that continues to reinforce this practice.

  3. Yes, I leave a few days(usually 2) for any remaining yeast/hop sediment to drop after transfer and then apply the gas. In the past when I was in a rush to apply gas right away I found it kept yeast etc… in suspension for the life of those kegs and drastically altered the flavor and clarity I was seeking.

  4. Right around 2 weeks then and they are ready to tap as I don’t mess with changing pressures as mentioned above and leave at normal serving pressure all the time.[/quote]

This was extremely helpful. So after purging and letting it settle for 2 days, you put the gas on your normal PSI for about 2 weeks? I have seen people purge at a very high PSI for a couple of days. How does that affect the beer?

I think you might be confusing the term purge. Purging is flushing the system with co2 and displacing the air in the keg or headspace.

I put about a half gallon of sanitizer in a keg and shake or roll it around. I then flip it upside down over a sink and pull the prv once and then depress the gas popping to sanitize those parts. I then flip back over and dispense the sanitizer through the beer post and a racking cane/ auto siphon. This replaces the air with co2.

After that, the keg purged and ready to fill. I fill with the siphon attached to the beer post and pull the prv to keep it flowing while the lid is closed.

I like to carbonate at serving pressure. I feel it results in finer bubbles and smoother carbonation.

[quote=“roffenburger”]I think you might be confusing the term purge. Purging is flushing the system with co2 and displacing the air in the keg or headspace.

I put about a half gallon of sanitizer in a keg and shake or roll it around. I then flip it upside down over a sink and pull the prv once and then depress the gas popping to sanitize those parts. I then flip back over and dispense the sanitizer through the beer post and a racking cane/ auto siphon. This replaces the air with co2.

After that, the keg purged and ready to fill. I fill with the siphon attached to the beer post and pull the prv to keep it flowing while the lid is closed.

I like to carbonate at serving pressure. I feel it results in finer bubbles and smoother carbonation.[/quote]

Woops you are right. I meant “I have seen people carbonate at a high PSI”. My plan was to purge the keg first, let sit, then carbonate. I just didn’t know if it was normal to let a keg sit for a while after purging.

The beer is two weeks old and has been dry hopping for the past week. Is it too early to keg if I do it on Sunday or Monday?

That’s not a bad timeline. I typically leave in fermented for 3 weeks and then cold crash and keg.

Two weeks total or two weeks plus dry hop?

[quote=“roffenburger”]That’s not a bad timeline. I typically leave in fermented for 3 weeks and then cold crash and keg.

Two weeks total or two weeks plus dry hop?[/quote]

Two weeks total so far. Maybe I leave it for another week in the fermenter?

For most ales I do 3 weeks in the fermentor and a week in the keg at 10 PSI and usually it’s ready to drink. Personally I have found if I try to force carb the taste seems off. IMO it always tastes better to let it age in the keg for at least a week or even two. I always purge the keg at least 3 times.

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