Explain Like I'm 5; carbonating through the "out" post?

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moldmaker

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I've been struggling with getting my cider's carbonation level right. I just read this tonight, where somebody was pushing gas through the dispense post. Bubbling the gas up through the bottom. Others say through the "in" post. Which is it? Does it matter?
 

bracconiere

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I've been struggling with getting my cider's carbonation level right. I just read this tonight, where somebody was pushing gas through the dispense post. Bubbling the gas up through the bottom. Others say through the "in" post. Which is it? Does it matter?


well kiddo, i'm not a elementary teacher...but i'd be thinking, like a hot air boolon gas rises. and co2 is somewhat soluble in water, so if it has to pass through the beer from the bottm more will dissolve quicker? since it's rising to the top? instead of having to sink down?


some people even use diffusion stones at the bottom with special lids! wait like you're five....this is tuff....


you know toddler, now you got me wondering why people don't carb with the keg laying on it's side too! :mug:
 

AzOr

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It shouldn’t matter. Carbonation is carbonation.
It’s similar to the carbonating stone method. IMO it does help carbonate quicker but for me, it’s not worth the hassle. My carb stone/corny lid has been collecting dust for a couple of years.

Remember that cider ain’t beer and doesn’t have the proteins etc. So the carb qualities are different. With cider I find that my co2 volumes can vary and it’s not as crucial as beer.
 

dmtaylor

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You can carbonate through the out line, but there is increased risk if you screw up of getting backflow into your air line, which is a whoops at best, and may require hose replacement at worst if you don’t like mold growing in your air line.
 

bracconiere

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You can carbonate through the out line, but there is increased risk if you screw up of getting backflow into your air line, which is a whoops at best, and may require hose replacement at worst if you don’t like mold growing in your air line.

good point
 

doug293cz

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You can carbonate through the out line, but there is increased risk if you screw up of getting backflow into your air line, which is a whoops at best, and may require hose replacement at worst if you don’t like mold growing in your air line.
And if you don't have fully functional check valves on your CO2 lines, beer can blow back into the regulator.

I saw this happen once at an LHBS where I submitted a keg for a function. I told them I wasn't sure if it was fully carbed yet, so the owner's son (or younger brother, not sure) decided to hook the CO2 line up to the beer out post. Well, the pressure in the keg was higher than the CO2 line pressure, and instantly there was beer blowing out of the regulator. Glad I'm not the one who hooked it up, and that it wasn't my regulator.

Needless to say, I would never risk hooking the CO2 up to a beer out post in my system.

If you want to carb quickly: chill the beer, hook it up to 30 psi for 36 hours, then vent the headspace, and set for chart pressure. Beer's ready in three days - not perfect, but good enough for impatient people. If that's not soon enough for you, you need to learn better pipeline management skills. The beer also tastes better with some time to settle after kegging.

Brew on :mug:
 
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moldmaker

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Thanks everyone for the replies. I went back down last night and adjusted it to 15psi. I'll let it sit for a couple more weeks. That method makes sense. The liquid is exposed to the gas regardless of if the gas is coming up through the bottom or being pushed down from the top.

I have not kegged/carbonated beer yet, just cider. The fridge is about 41F, so the chart says I should get 2.7 volumes of CO2. Having nothing to compare to, this seems like a good middle-of-the-road.

In the past, my biggest mistake was not venting the keg when I changed regulator settings. I would set it to 30psi to carbonate fast and then dial it down to 8psi to serve and wonder why I was getting nothing but foam.
 
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I like to burst carb @ 60psi for 24 hours, then I'll forget about it for three days, and then curse my way through a few angry foamy pints. At that point I'll fit a spunding valve set to ~8 psi and then forget about it for a week or two.

Long story short, charge it with serving pressure and do something else for two weeks.

Impatient? Buy some beer to tide you over.
 
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I carb in the beer out. I attach my gas to the beer out after transfer and put it in my keggorator. Set gas to 2-3 PSI and every day go boost it a couple PSI. As the beer cools down it draws in gas. By the time I'm at 10-12 PSI it's carved beautifully...

Cheers
Jay
 

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moldmaker

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It's been 8 days at 39F and15psi. At 8psi, it serves with a slight foaming, but it still doesn't really taste carbonated. Do I let it go another week or turn the pressure up?
 
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It's been 8 days at 39F and15psi. At 8psi, it serves with a slight foaming, but it still doesn't really taste carbonated. Do I let it go another week or turn the pressure up?
If you start fiddling with higher pressure now you're really risking overcarbed beer. I'd recommend letting it ride a few more days, shouldn't take another whole week.
 

doug293cz

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If you start fiddling with higher pressure now you're really risking overcarbed beer. I'd recommend letting it ride a few more days, shouldn't take another whole week.
I beg to differ. You pick up about:
63% of full carbonation after 1 week​
86% of full carbonation after 2 weeks​
95% of full carbonation after 3 weeks​
98% of full carbonation after 4 weeks​
99% of full carbonation after 5 weeks​
This assumes a "full" 5 gal keg, with the beer level not above the cylindrical zone of the keg wall, and a 1 week time constant.

Brew on :mug:
 
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moldmaker

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It's a little over 4 gallons. I'll let it sit and keep trying it. My mistake here was not starting it sooner so it would be ready by now!
 
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I beg to differ. You pick up about:
63% of full carbonation after 1 week​
86% of full carbonation after 2 weeks​
95% of full carbonation after 3 weeks​
98% of full carbonation after 4 weeks​
99% of full carbonation after 5 weeks​
This assumes a "full" 5 gal keg, with the beer level not above the cylindrical zone of the keg wall, and a 1 week time constant.

Brew on :mug:
Thank you captain gassy math, so what do you recommend? My advice was, don't mess with it. Do you have a fool-proofier method?
 
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sibelman

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I want my beer (oops, I mean cider) carbed fast! Oh, dang, not over-carbed! My goodness, what's a kegger to do? It can be something of a tightrope, eh? <sigh> Sorry but I have no magic formula. At least there's no hop creep with cider.
 

doug293cz

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Thank you captain gassy math, so what do you recommend? My advice was, don't mess with it. Do you have a fool-proofier method?
I wasn't disagreeing with your recommendation to just let it sit, but rather trying to give a more realistic timeframe for "set and forget" carbonation. I agree, at this point, where there is no easy way to know how much carbonation is currently in the beverage, just leaving it alone is best.

As an alternate, OP could agitate the keg at the desired pressure and temp, to speed the absorption of CO2. There is no way to over carb if you agitate at equilibrium pressure. The risk comes when agitating at higher than equilibrium pressure. If you have yeast, and other junk settled at the bottom of the keg, you may not want to agitate the keg, as you will stir up all the trub.

Brew on :mug:
 

doug293cz

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I want my beer (oops, I mean cider) carbed fast! Oh, dang, not over-carbed! My goodness, what's a kegger to do? It can be something of a tightrope, eh? <sigh> Sorry but I have no magic formula. At least there's no hop creep with cider.
If you want to carbonate quickly, without having to worry about over carbonating, there are two methods:
  1. Agitate the keg at the chart pressure for the desired carb level and the current beverage temperature. Usually this works best if you agitate until you don't hear gas flowing, wait a few minutes, then repeat. When you no longer hear gas start to flow when you start agitating, you are pretty much done. You may not be at equilibrium, but you should be "close enough."
  2. Use a carbonation stone that introduces CO2 as bubbles at the bottom of the keg. You can get keg lids that have a gas inlet to feed a carb stone. When using a stone, it's best to start at 0 pressure, and slowly ramp up until you hear gas flow. Note the pressure at which gas started to flow. Then wait until you no longer hear gas, and then raise the pressure ~1 psi. Continue this until the gauge pressure is the chart pressure plus the pressure at which you first heard gas start flowing at the beginning of the process. Finally, hook the CO2 up to the normal gas in post for serving.
Both of the above methods should get you beer carbed in less than an hour. Beer still might not be ready to drink due to suspended particulates (yeast, and other junk.)

If you can wait a few days, chill, then 30 psi for 36 hours, then vent and set to chart pressure is unlikely to over carb. Usually drinkable (even if not optimal) by day 3. This method doesn't stir up trub from the bottom of the keg.

Brew on :mug:
 
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