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Over filling a keg

I have a couple of friends that are just getting started brewing and kegging. They first keg the beer and carbonate then bottle with the beer gun.

They are saying that the beers are not carbonated as much as they should be I made sure the last beer had the right psi and temp along with 12 days at 34 degs but I did not check how full they filled the kegs.

The only thing I can think of is that they over filled the keg past the bottom of the gas in tube.
There 5 gallon carboys were full up to the neck and the sucked up every drop.\

I’m going to have to check how long of a tube it has on it first then I’ll have them put a piece of hose and a air stone on and drop it to the bottom of the keg.

Does this make sense to anyone or am I losing it ?

It sounds reasonable.

But timeframe is not always set in stone when it comes to force carbing, so it could also be that it just needed more time, regardless of vloume.

I do find the the amount of head space makes a difference in how quickly a keg carbs up, so your theory sounds fine. Just not %100 certain.

There are times when it seems like my beers carbonate in a few days and times when it takes them 10-14 days to become carbonated. I don’t know why that happens. I seal the kegs well and there aren’t leaks in my system…
12 days doesn’t seem like quite enough time for the co2 to be fully dissolved. It’s close, though. I don’t know why an overfilled keg would carbonate in less time than an underfilled keg.

Head space makes some difference in carbing time, but surface area makes a bigger one. The rate at which the gas can dissolve into the beer is directly related to the area of the gas/beer interface. That might make you think that filling above the level of the gas post means that the surface area is just the small circle in the post itself, but that is not actually the case. As the gas at the very top dissolves into the beer, there are less molecules to keep the pressure up and the gas will bubble in through the post and replenish the depleted gas in the head area. So it doesn’t actually matter if the beer is slightly above or slightly below the level of the gas post.

Head space matters mostly because if you have a large headspace, you have less beer to carb, so it happens faster.

There are two easy ways to increase the surface area of the interface so the keg will carb faster:

  1. lay the keg on it’s side. This works best if the keg isn’t too full, but you have to make sure you have a check valve on the gas line so beer doesn’t back into it.

  2. Shake the keg. This can give you a fully carbed keg in 10-15 minutes. When you shake, you are creating a huge interface area (the area of every bubble and droplet counts).

But I think the problem your friends have is simpler than that. Bottling after kegging results in some loss of carbonation, the exact amount dependent on their technique. That is where I suspect the problem is.

[quote=“Beersk”]There are times when it seems like my beers carbonate in a few days and times when it takes them 10-14 days to become carbonated. I don’t know why that happens. I seal the kegs well and there aren’t leaks in my system…
12 days doesn’t seem like quite enough time for the co2 to be fully dissolved. It’s close, though. I don’t know why an overfilled keg would carbonate in less time than an underfilled keg.[/quote]
Hop oil? I find that dry hopped beers take longer because a layer of oil forms on the surface that inhibits the transfer of gas to the beer.

[quote=“rebuiltcellars”][quote=“Beersk”]There are times when it seems like my beers carbonate in a few days and times when it takes them 10-14 days to become carbonated. I don’t know why that happens. I seal the kegs well and there aren’t leaks in my system…
12 days doesn’t seem like quite enough time for the co2 to be fully dissolved. It’s close, though. I don’t know why an overfilled keg would carbonate in less time than an underfilled keg.[/quote]
Hop oil? I find that dry hopped beers take longer because a layer of oil forms on the surface that inhibits the transfer of gas to the beer.[/quote]
Oh, that very well could be. I had an IPA recently that took 2+ weeks to carbonate at 10PSI in at 38F. It was kind of frustrating actually.

[quote=“Beersk”][quote=“rebuiltcellars”][quote=“Beersk”]There are times when it seems like my beers carbonate in a few days and times when it takes them 10-14 days to become carbonated. I don’t know why that happens. I seal the kegs well and there aren’t leaks in my system…
12 days doesn’t seem like quite enough time for the co2 to be fully dissolved. It’s close, though. I don’t know why an overfilled keg would carbonate in less time than an underfilled keg.[/quote]
Hop oil? I find that dry hopped beers take longer because a layer of oil forms on the surface that inhibits the transfer of gas to the beer.[/quote]
Oh, that very well could be. I had an IPA recently that took 2+ weeks to carbonate at 10PSI in at 38F. It was kind of frustrating actually.[/quote]
You bring up another variable: temperature. Beer will carb faster if it is colder because it will hold more gas at lower temperatures.

This one an oatmeal stout was carbed at 11psi at 34 degs and the secondary was also at 34 deg before it was racked it to the keg.

I have another beer that is nearly flat after 5 days in the keg. It’s a vienna lager. Pretty sure there isn’t a leak. The co2 tank is almost out, but it’s not in the red yet (at room temp), so I don’t think it’s that. Oh well. Give it time I guess. Sometimes, with as long as it takes to carbonate in a keg, I feel like I might as well bottle and produce my own co2.
11psi at 34F I would think would carbonate pretty quickly. I’m at around 38F and 9 or 10psi.

I think we have the answer, the keg posts were loose on the kegs they were filling from using the beer gun there by not getting enough CO2 in the bottles. They probable didn’t get the beer carbonated prior to filling either I was wondering why they used so much CO2.

They had a full 15 Lb tank and used over half of it carbonating 2 kegs.

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