Over-carbonation problem in corny

[gobuchul]

I don't normally bother with secondary fermentation but when I kegged a 7% IPA I primed with sugar.

It had been in the keg for a week or so and I connected it up to my CO2 and tried a bit.

The beer was nowhere near ready, needed at least 2 more weeks. So I gave it a fairly high pressure blast of CO2, about 3 bar or so and disconnected the gas. It was left in the corner of my kitchen, around 19C.

Well after 2 weeks, I connected it yesterday and it went crazy. Pushing beer up the gas line. Tried to push the beer back but even at 3 bar it didn't do anything. So I manually vented the keg, quite a bit of beer foam coming out. I couldn't get to stop last night. So today, I been repeatedly venting it until it stops hissing. However, after 30 minutes or so, there again is gas pressure.

What's going on?

What's the best thing to do about it?

[IPA]

I don't normally bother with secondary fermentation but when I kegged a 7% IPA I primed with sugar.

It had been in the keg for a week or so and I connected it up to my CO2 and tried a bit.

The beer was nowhere near ready, needed at least 2 more weeks. So I gave it a fairly high pressure blast of CO2, about 3 bar or so and disconnected the gas. It was left in the corner of my kitchen, around 19C.

Well after 2 weeks, I connected it yesterday and it went crazy. Pushing beer up the gas line. Tried to push the beer back but even at 3 bar it didn't do anything. So I manually vented the keg, quite a bit of beer foam coming out. I couldn't get to stop last night. So today, I been repeatedly venting it until it stops hissing. However, after 30 minutes or so, there again is gas pressure.

What's going on?

Buy the spunding device from the MaltMiller and your problems will be over

What's the best thing to do about it?

[IPA]

I don't normally bother with secondary fermentation but when I kegged a 7% IPA I primed with sugar.

It had been in the keg for a week or so and I connected it up to my CO2 and tried a bit.

The beer was nowhere near ready, needed at least 2 more weeks. So I gave it a fairly high pressure blast of CO2, about 3 bar or so and disconnected the gas. It was left in the corner of my kitchen, around 19C.

Well after 2 weeks, I connected it yesterday and it went crazy. Pushing beer up the gas line. Tried to push the beer back but even at 3 bar it didn't do anything. So I manually vented the keg, quite a bit of beer foam coming out. I couldn't get to stop last night. So today, I been repeatedly venting it until it stops hissing. However, after 30 minutes or so, there again is gas pressure.

What's going on?



What's the best thing to do about it?

Buy a spunding device from the MaltMiller and your problems will be over.

[PeeBee]

Bit simpler than waiting for an order to arrive:

You vent the over-pressure and 1/2 hour later its back. This is perfectly normal. You vent the gas in head space, but not the gas already dissolved in the beer. Getting the gas out of the beer is going to take longer; much longer! Keep at it, venting the gas, waiting for it to rebuild, vent again … It will soon take hours for the pressure to build back up, so it wont take up a huge chunk of time. When I had a keg at 90-100PSI (and that was only 30g sugar priming in 20L! But the FG was 1.023 and it had been matured for six months) it took a few days to get it under control, but in the end I was only venting once or twice a day.

After my "incident" I built apparatus to do the job anytime, using a water filter housing as a "trap" and a needle valve to slowly release the gas as it builds back. I build needle valves into my dispensing arrangements now so I can deal with even slight over-pressures as and when they occur.

[Robwalkeragain]

Any hop matter in the beer? Might be supplying a nucleation site, although just a side thing and probably not the main cause.

[IPA]

Bit simpler than waiting for an order to arrive:

You vent the over-pressure and 1/2 hour later its back. This is perfectly normal. You vent the gas in head space, but not the gas already dissolved in the beer. Getting the gas out of the beer is going to take longer; much longer! Keep at it, venting the gas, waiting for it to rebuild, vent again … It will soon take hours for the pressure to build back up, so it wont take up a huge chunk of time. When I had a keg at 90-100PSI (and that was only 30g sugar priming in 20L! But the FG was 1.023 and it had been matured for six months) it took a few days to get it under control, but in the end I was only venting once or twice a day.

After my "incident" I built apparatus to do the job anytime, using a water filter housing as a "trap" and a needle valve to slowly release the gas as it builds back. I build needle valves into my dispensing arrangements now so I can deal with even slight over-pressures as and when they occur.

Orders from the MaltMiller arrive next day. Even here, a thousand kilometres from Swindon, they arrive in 48 hours.

[PeeBee]

Orders from the MaltMiller arrive next day. Even here, a thousand kilometres from Swindon, they arrive in 48 hours.

Fair enough. My last order from them did take a few days. But on the day it was to be sent I changed my mind, swapped bits about, and was geneally a right ...

He's very accommodating is Rob at MM. And despite being as annoying as I could, he never turns around and tells you what he might think of you!

[Kev888]

What's going on?

3-bar was probably twice what was needed to seat the lid, but it won't have added a huge amount of carbonation if there was a normal amount of headspace in the keg. So I'd guess that either the priming sugars were too generous (for cornies) and/or the yeast sneakily fermented a bit more of the original wort once kegged.

As mentioned, it takes a while for the carbonation to come out of suspension, so pressure will build up again after the keg is re-sealed. It either needs to be vented constantly or frequently to make much difference; either manually or with a valve, both work. Some people will roll the keg between ventings, to speed up release of CO2 from the beer, but this in itself can make foam (and stir up any yeast) so its a matter of preference.

If the keg is at room temperature, it is possible that chilling will make it possible to serve beer - drawing a pint every so often will be a little like venting. If so, don't connect the CO2 until it has calmed down, and if/when connected then reduce the CO2's pressure according to the beer's temperature. A lot of foam issues at this time of year are due to over force-carbonating, because kegs cool down and the pressure isn't reduced accordingly, but it doesn't sound like this is the case here.

[f00b4r]

Edit: NM should have read more carefully.

[MTW]

Only just seen this. Vent, and stick a very brief burst of gas down the OUT tube. This nucleates the excess gas better than anything else i found. Switch disconnects first if it helps to get it on and off. Repeat, at least until foam at the vent means a while off.