naturally carbonating a keg

[amcclai7]

I brewed a London Pride clone a while back. When it was done fermenting I siphoned it over to a keg and added about 6.5 oz of DME. (I did some research and it appears that this may have been a bit too much) The plan was to let it naturally carbonate and then serve under about 3 psi. Just enough to push the beer out and fill up the headspace to prevent oxidation. I went to pull the first pint today and even without the CO2 tank hooked up it came out as all foam. I had to fill a 32oz pitcher just to get a full pint. What should I do? As i see it I have two main options.

Keep serving without the CO2 hooked up and hope the foaming goes down. The risks of this include wasting beer and oxidation, although the beer is so carbed right now it might be filling up the headspace on its own.

2. Use a pin and push down the gas input to let off the excess pressure and then serve as I had planned. The main risk of this is letting of too much pressure and letting the beer go flat in which case I would have to use CO2 from the tank to carb the beer. I would like to avoid this b/c the whole point was to have a naturally carbed cask style english ale.

Thoughts?

The good news: Even with all the foaming the beer tastes great and drinks like an authentic English cask.

 

[longhornbarrett]

Keep releasing the pressure using the release valve until it gets to where you want it,
I brew very similar beers and serve them on nitrogen,
When I do I carbonate using 2 oz of sugar and that is perfect for the carbonation

 

[billl]

Before you do anything, confirm it's overcarbed. Make sure it is chilled at least 24 hours. Vent the keg, put 3 lbs pressure on it and serve. If its still a mess, take the gas off, vent, let it sit a few hours. Vent again. Repeat until the carb level drops to what you want.

Unless you plan to drink it all in one sitting though, you want to keep the serving pressure the same as you would have used to carb it. eg 10-12 psi depending on temp. If you just set it at 3psi, you'll have flat beer in short order.

 

[Weezy]

I've thought of doing this but what about all the oxygen that's in the headspace when you start? are you going to purge the keg first? In my mind, if I'm going to that trouble, why not just carb with co2 that I'm already futzing with?

 

[amcclai7]

I've thought of doing this but what about all the oxygen that's in the headspace when you start? are you going to purge the keg first? In my mind, if I'm going to that trouble, why not just carb with co2 that I'm already futzing with?

ab/c if you carb with cO2 you will get fizzy american beer. I want as authenic of an English cask ale as I can get. Those are carbonated naturally and that's what I am trying to achieve. As far as the oxygen starting off, I don't think there would be any. The DME I added caused the beer to carbonate and CO2 is whats in the headspace from the beginnning.

 

[JuanMoore]

If you want to serve it like an English cask ale, then you need to carb it like English cask ale, which is to say very low carbonation. In order to prevent foamy pours, your serving pressure needs to match the equilibrium pressure of the carbonation. For example, a serving pressure of 3 psi and serving temp of 40° would be ~1.6-1.7 vol, and would require 1.8-1.9 oz of priming sugar per 5 gal. For a serving temp of 45° you'd want 1.5 vol, which equals ~1.5 oz of priming sugar.

One solution for this keg is to remove it from the gas and bleed it periodically over the course of a couple days until the carbonation level drops to your target level. The other solution is to increase the serving pressure until it matches the carbonation level at your serving temp, assuming your lines are long enough to handle the pressure at that temp.

 

[Weezy]

ab/c if you carb with cO2 you will get fizzy american beer. I want as authenic of an English cask ale as I can get. Those are carbonated naturally and that's what I am trying to achieve. As far as the oxygen starting off, I don't think there would be any. The DME I added caused the beer to carbonate and CO2 is whats in the headspace from the beginnning.

Where did the air go? The co2 isn't filling a vacuum, right? maybe it doesn't matter. Real ale is meant to be drank when tapped anyways. No time to oxidize. Never mind.

 

[longhornbarrett]

Where did the air go? The co2 isn't filling a vacuum, right? maybe it doesn't matter. Real ale is meant to be drank when tapped anyways. No time to oxidize. Never mind.

Put the sugar or the dme in then hook it up to gas and purge it then remove it from the had and let it purge naturally

 

[billl]

"Where did the air go? The co2 isn't filling a vacuum, right?"

The yeast consume it while eating up the priming sugar. It's just like bottle conditioning.

 

[Curtis2010]

See thread(s) on Spunding Valve.

 

[Weezy]

Yeast use oxygen to reproduce, not to eat. They reproduce when they perceive the presence of so much food that they need help to eat it all. I'm not sure that's the case with priming sugar. But I could be wrong!

 

[peterj]

ab/c if you carb with cO2 you will get fizzy american beer. I want as authenic of an English cask ale as I can get. Those are carbonated naturally and that's what I am trying to achieve. As far as the oxygen starting off, I don't think there would be any. The DME I added caused the beer to carbonate and CO2 is whats in the headspace from the beginnning.

I get the ethos of what you're going for but practically speaking CO2 is CO2. It doesn't matter if it comes from a tank or if the yeast produce it. What matters is how much CO2 you put in the beer, and you put too much in and made "fizzy american beer". You need to bleed off the excess CO2 until it reaches the level you like. This is great advice and you should follow it:

If you want to serve it like an English cask ale, then you need to carb it like English cask ale, which is to say very low carbonation. In order to prevent foamy pours, your serving pressure needs to match the equilibrium pressure of the carbonation. For example, a serving pressure of 3 psi and serving temp of 40° would be ~1.6-1.7 vol, and would require 1.8-1.9 oz of priming sugar per 5 gal. For a serving temp of 45° you'd want 1.5 vol, which equals ~1.5 oz of priming sugar.

One solution for this keg is to remove it from the gas and bleed it periodically over the course of a couple days until the carbonation level drops to your target level. The other solution is to increase the serving pressure until it matches the carbonation level at your serving temp, assuming your lines are long enough to handle the pressure at that temp.

Here's a calculator for figuring out psi, temperature, and volumes of CO2: http://www.brewersfriend.com/keg-carbonation-calculator/.

It may take a while to bleed off the excess CO2 because you have to bleed off the pressure in the headspace then allow it to come to equilibrium and bleed off some more. I've heard of people doing this over the course of days.

 

[billl]

Yeast use oxygen to reproduce, not to eat. They reproduce when they perceive the presence of so much food that they need help to eat it all. I'm not sure that's the case with priming sugar. But I could be wrong!

No, yeast use O2 whenever it is available. It allows them to reproduce much faster, not the other way around. Yeast consuming the available O2 is what makes bottle conditioned beer so stable.

 

[laughingboysbrew]

I want as authenic of an English cask ale as I can get.

If you truly want authentic, you need prime (either rack before FG or prime as you did, though I would use Dextrose not DME) then store it at 13C (54F) "cellar temp". This is important because it will result in the proper condition (carbonation) of the beer. After secondary fermentation completes, you would then vent off (burp the keg) any extra gas multiple times over the course of 2-3 days as CO2 comes out of solution and the beer stabilizes at the right condition. When no more gas comes out, your beer would be naturally carbonated to 1.1 vols at 13C.

The challenge comes in serving. If you hook up any CO2, kiss authenticity goodbye (it's a corner you don't have to cut). Next best thing people do is tilt the keg on it's side and hook a picnic tap or faucet up to the gas in valve. You'll have to let a little air in as you go. Best solution is to invest in a beer engine and pull the beer out.

All of the above methods are authentic to style and serving. However, as you let O2 in it will oxidize the beer. This is actually TRUE to the style/authenticity of cask beer. Cask beer matures on a bell curve with the best beer somewhat oxidized over a day or so. After 4 days, you better have finished the beer.

If you want it to last a little longer, hook up an aspirator valve with CO2 (set to 1-2psi) It will 'allow' atmospheric pressure of CO2 to enter only as you pull/pour beer out. But it will never push any beer out. The blanket of CO2 does nothing to the condition of the beer either, just prevents oxidization. While technically not as authentic, most people would agree it's a somewhat acceptable cheat to enjoy the beer longer.

Cask conditioned ales are the reason I got into brewing.