Struggling with carbonation in keg

[bucketheadmn]

I brew 2.5 gallon BIAB batches and ferment in a 5 gallon siphonless wide mouth bubbler. I know that the beer I am making tastes great as I have bottled a couple of batches and they turned our really good.

So I am three batches into kegging and I am drinking flatish beer. I have read quite a lot of how to carb, but hoping someone can point to the error in my ways. When done with fermentation I hook up my hose to the fermentor and then rack directly to my keg. For my keg set up I am using a ball lock corny keg with 10 feet of 3/16" connected to a picnic tap in a fridge in the mid 40's. Here is what I did with each of the three batches:

1 - I set it at 30 psi for a few days and then dialed it down to 10 leaving it there. This one was flat and had a off taste - chalked it up to something else and dumped the batch (only time I have ever done that!) as I had only a single keg at this point and wanted to get something good in it!

2 - I set it again at 30psi for a couple of days and dialed it down to 10psi. At first I thought I might have over carbed it as there was an off taste. So I followed the process I read in a few places to let it get warm and pull the pressure pin throughout a couple of days. I then put it back in the fridge set at 12psi. While drinkable there was something off with the carbonation the whole batch.

3 - I kegged this batch 6 days ago (brewed it 9/9) and set it at 12psi thinking I am not in a rush at all with this (who am I kidding, I want to drink it!). While pouring today there is a decent head, but the beer still tastes flat. The flavor and aroma is also not as nice as it was before going into the keg.

What should I be doing or checking in my system? I used the carb charts to set it at 12 psi, but none of the charts I found mention how long it takes to get fully carbed up. Am I being impatient? Should I be doing this another way?

 

[FunkedOut]

Patience is king. In a week or two, that beer will not be flat.
Also, try 13psig. Maybe the gauge on the regulator is off or maybe you like a little more carb?

Can't really help with the off taste. Are the gas lines clean?

 

[bucketheadmn]

Patience is king. In a week or two, that beer will not be flat.
Also, try 13psig. Maybe the gauge on the regulator is off or maybe you like a little more carb?

Can't really help with the off taste. Are the gas lines clean?

Well I did not clean the gas line, just hooked it up. Guess I did not realize it needed to be cleaned. Soak it in pbw or starsan? Or what is the best way to clean it?

 

[Horseflesh]

If your gas line was new then I don't think it needs cleaning. If it's old I'd just replace it, it's a short run and a little tubing is cheap. When you do clean tubing, I would use BLC. (Beer Line Cleaner, a basic solution.)

Double check your serving line length with this calculator.
http://www.mikesoltys.com/2012/09/17/determining-proper-hose-length-for-your-kegerator/

You can also shake or rock the keg, while it's hooked up, to dissolve the gas more quickly. It takes some practice to not over-do it. 6-10 minutes of agitating 36-40F beer under 30 psi should get you something sort of drinkable in my experience. Let it settle before you vent and reset the pressure, though, or you'll blow foam.

Lastly, if you want some cold carbed beer NOW, or you want to test different carb levels, get a carbonation cap. You can quickly carb a couple servings of beer in a 2 liter soda bottle this way. I shoot for a batch size of 5.25 - 5.5 gallons so I have a little beer left over after kegging, which I force carb and enjoy right away. This also gives me a flavor reference without the keg being involved, nice for troubleshooting.

 

[Brewsader1]

Can you describe the off flavors you noticed with each batch? Were they the same with each one?

For carbing, this is a useful chart to figure out appropriate CO2 volumes. Match up your pressure with the temperature for the desired carb level. http://www.kegerators.com/carbonation-table.php

 

[bucketheadmn]

Can you describe the off flavors you noticed with each batch? Were they the same with each one?

For carbing, this is a useful chart to figure out appropriate CO2 volumes. Match up your pressure with the temperature for the desired carb level. http://www.kegerators.com/carbonation-table.php

As far as the off flavors the closest I can come to is no hop flavor with my two most recent IPAs. The two recent batches kinda had the same taste, but were dry hopped and boiled with different hops.

And I have seen that chart - the thing that is no good about it is that it does not mention a time frame, which is where I am unsure. I have set it in the green area with the 12psi and 44 degree fridge.

 

[Brewsader1]

I'd say it'd be at full carb level by the end of 2 weeks (1 week should be mostly there, but judge by taste). I personally don't like the rolling of kegs and high pressure methods, but if you really want to push it, set it at 30 psi for 24 hours then set the regulator to the appropriate psi and release the head pressure. If your beer is only 2-3 weeks old, it could use the extra week or two of pressurization and conditioning anyways.

Regarding the off flavors...it could be infection, it could be oxidation, or it could be recipe/process. The method I've found best was learned from Drew Beechum. Fill your keg with sanitizer, then push it to another keg with CO2. Your keg is then completely purged with CO2. Given that you are doing 2.5 gal batches, the additional head space leaves lots of room for air and thus oxidation. The other suggestion is that if you are not in a home-brew club, see if you have one close by and if not, see if you can get a knowledgable person or professional brewer to taste the beer and give you feedback on what it may be. Or send it in to a big competition.

Lastly, if two weeks go by in your kegging and you still have flat beer, you may have small leaks in the keg. There are plenty of posts about this and methods of troubleshooting to figure out how/where. If this is what it is, post back here as well and we'll help you troubleshoot at it. Good luck and once you figure it out, you'll be a happy camper!!

 

[FunkedOut]

A small leak in the keg would explain the combination of flat beer and loss of hop aroma.

 

[bucketheadmn]

I'd say it'd be at full carb level by the end of 2 weeks (1 week should be mostly there, but judge by taste). I personally don't like the rolling of kegs and high pressure methods, but if you really want to push it, set it at 30 psi for 24 hours then set the regulator to the appropriate psi and release the head pressure. If your beer is only 2-3 weeks old, it could use the extra week or two of pressurization and conditioning anyways.

Regarding the off flavors...it could be infection, it could be oxidation, or it could be recipe/process. The method I've found best was learned from Drew Beechum. Fill your keg with sanitizer, then push it to another keg with CO2. Your keg is then completely purged with CO2. Given that you are doing 2.5 gal batches, the additional head space leaves lots of room for air and thus oxidation. The other suggestion is that if you are not in a home-brew club, see if you have one close by and if not, see if you can get a knowledgable person or professional brewer to taste the beer and give you feedback on what it may be. Or send it in to a big competition.

Lastly, if two weeks go by in your kegging and you still have flat beer, you may have small leaks in the keg. There are plenty of posts about this and methods of troubleshooting to figure out how/where. If this is what it is, post back here as well and we'll help you troubleshoot at it. Good luck and once you figure it out, you'll be a happy camper!!

My process this last time was to clean keg with pbw then fill with starsan. Using co2 I then pushed out all the starsan. I opened the top to put a line in from the spigot on my fermentor which was resting on the bottom of the keg and then filled the keg. Once all my beer was in the keg I pressurized it and then purged it by pulling the pin - did that twice thinking that would get rid of all the oxygen. Then I set it at 12psi and have left it.

A small leak in the keg would explain the combination of flat beer and loss of hop aroma.

My keg does not lose any pressure throughout the day at all - I set it at 12psi and it stays at 12 psi. Could there still be a leak? I will do some searching/reading about leaks in a keg and how to find them. Thanks

 

[Northern_Brewer]

As far as the off flavors the closest I can come to is no hop flavor with my two most recent IPAs.

Obvious question at this time of year is how fresh are your hops, have they been stored well - cold, with no oxygen?

 

[bucketheadmn]

Obvious question at this time of year is how fresh are your hops, have they been stored well - cold, with no oxygen?

Fresh as you can buy at Northern Brewer in person in their 1 ounce retail bags. I have been buying hops by the ounce and each brew has used a brand new unopened bag that I have kept in the fridge for no more than 3 weeks after buying them from NB.

 

[doug293cz]

My process this last time was to clean keg with pbw then fill with starsan. Using co2 I then pushed out all the starsan. I opened the top to put a line in from the spigot on my fermentor which was resting on the bottom of the keg and then filled the keg. Once all my beer was in the keg I pressurized it and then purged it by pulling the pin - did that twice thinking that would get rid of all the oxygen. Then I set it at 12psi and have left it.

That amount of purging is totally inadequate to remove enough O2 to control oxidation over time. Commercial breweries target less than 200 ppb (0.2 ppm) total packaged oxygen (TPO) (ref.) The table and chart below show residual O2 in the headspace after various numbers of purge cycles at several different CO2 pressures. A purge cycle involves pressurizing the keg until the CO2 pressure stabilizes, shutting off the CO2, and venting all the pressure in the headspace.





I can't estimate from your purge process description just how much air you have left in the headspace, but any air in the headspace will reduce the effective CO2 pressure by the same percentage as the air percentage of the total headspace gas. This could cause significant under carbing for high percentages of residual air.

My keg does not lose any pressure throughout the day at all - I set it at 12psi and it stays at 12 psi. Could there still be a leak? I will do some searching/reading about leaks in a keg and how to find them. Thanks

Doesn't sound like a leak problem. In order for a leak to prevent proper carbonation, the leak has to be fast enough that you can't get the keg up to full pressure. With that fast a leak your CO2 will run out way before two weeks.

With the "set and forget" force carbonation method, it takes about three weeks to be "fully" carbed, but you should be almost fully carbed after about two weeks. And, you might be drinkable after one week.

Brew on

 

[bucketheadmn]

I can't estimate from your purge process description just how much air you have left in the headspace, but any air in the headspace will reduce the effective CO2 pressure by the same percentage as the air percentage of the total headspace gas. This could cause significant under carbing for high percentages of residual air.


Doesn't sound like a leak problem. In order for a leak to prevent proper carbonation, the leak has to be fast enough that you can't get the keg up to full pressure. With that fast a leak you CO2 will run out way before two weeks.

With the "set and forget" force carbonation method, it takes about three weeks to be "fully" carbed, but you should be almost fully carbed after about two weeks. And, you might be drinkable after one week.

Brew on

Thanks for the in depth response! It looks like I should be purging upwards of 20 times with a set it and forget it of 12 psi!!! How often should I be purging to get the total number of purges I need - a few times a day? Once a day for a couple of weeks?

I guess my main question is then what is your psi and purge process for carbing up a beer in your kegs doug293cz? I would love to have a process down so my beer tastes as good out of the keg as it has been out of the bottles.

I would love to have someone write a "how-to for dummies" in regards to the set it and forget it with purging and when the beer is ready. There is a ton of different information out there about quick carbing, what to set your psi at for temp in fridge, etc.. But nothing like here DO THIS for perfectly carbed beer every time.

 

[SanPancho]

My process this last time was to clean keg with pbw then fill with starsan. Using co2 I then pushed out all the starsan. I opened the top to put a line in from the spigot on my fermentor which was resting on the bottom of the keg and then filled the keg. Once all my beer was in the keg I pressurized it and then purged it by pulling the pin - did that twice thinking that would get rid of all the oxygen. Then I set it at 12psi and have left it.



My keg does not lose any pressure throughout the day at all - I set it at 12psi and it stays at 12 psi. Could there still be a leak? I will do some searching/reading about leaks in a keg and how to find them. Thanks

Few things- see if you can get a 1/2" hose on your spigot, then unscrew the beer-in post and quickly connect hose to drain into keg. Less o2 getting in that way. When flow slows pull the ring to release some gas and make room for more beer in keg. If you really wanna be complete you'll need make up air for the fermenter (co2) to keep the beer from pulling a ton of air into it while it drains.

And when you say you leave the keg at 12psi and it holds that pressure is that with the gas supply still attached to the keg?

I ask because if gas is disconnected and keg pressure doesnt drop as beer absorbs the gas then something is wrong. (Physics). And if gas stays connected and beer is still flat then something is also going wrong.(leak most likely).

 

[bucketheadmn]

Few things- see if you can get a 1/2" hose on your spigot, then unscrew the beer-in post and quickly connect hose to drain into keg. Less o2 getting in that way. When flow slows pull the ring to release some gas and make room for more beer in keg. If you really wanna be complete you'll need make up air for the fermenter (co2) to keep the beer from pulling a ton of air into it while it drains.

And when you say you leave the keg at 12psi and it holds that pressure is that with the gas supply still attached to the keg?

I ask because if gas is disconnected and keg pressure doesnt drop as beer absorbs the gas then something is wrong. (Physics). And if gas stays connected and beer is still flat then something is also going wrong.(leak most likely).

The other day I turned the gas off, but left it connected, and left it off for just over 12 hours or so I remember right - the PSI might have gone down 1 or 2, it was not much. That is how I figured there was no leak.

I just bought a 2nd keg so my next batch I will be trying in that keg, but it'll be a few weeks until I rack that as I am not brewing it until next weekend.

 

[SanPancho]

The other day I turned the gas off, but left it connected, and left it off for just over 12 hours or so I remember right - the PSI might have gone down 1 or 2, it was not much. That is how I figured there was no leak.

I just bought a 2nd keg so my next batch I will be trying in that keg, but it'll be a few weeks until I rack that as I am not brewing it until next weekend.

Wait. Do you mean you turned off the gas at the tank but left the line connected to keg? If the psi went down that doesnt mean there wasn't a leak. Could be a slow leak from keg/gas line, or diffusion into beer. Or both.

The only way to be certain theres no leak is a psi test on an empty keg. And even then on a corny it only means your gas posts dont leak. The lid is opened frequently and needs to be resealed each time, obviously. Thats where i see most of my leaks. Spraying star san or something foamy is a good way to make sure it's sealed. And its a good idea to do the same to your gas line if possible. Most of us use barbs and clamps to connect the tubing and they can leak too, slowly.

ALWAYS pressure test all components before going into service. I spaced out and let our 5bbl brites go into service with leaks all over the place. Gas connections, check valves, carb stones, quick connects, gauge threads, etc. Total nightmare. Luckily one tank was empty so it was pressure test, repair, test again, then clean, transfer and carb again. Then repeat three times. Embarrassing mistake to make. So give your new keg the full once over before you use it. Better to find a leak in an empty keg than when you're expecting delicious beer.

 

[bucketheadmn]

Wait. Do you mean you turned off the gas at the tank but left the line connected to keg? If the psi went down that doesnt mean there wasn't a leak. Could be a slow leak from keg/gas line, or diffusion into beer. Or both.

The only way to be certain theres no leak is a psi test on an empty keg. And even then on a corny it only means your gas posts dont leak. The lid is opened frequently and needs to be resealed each time, obviously. Thats where i see most of my leaks. Spraying star san or something foamy is a good way to make sure it's sealed. And its a good idea to do the same to your gas line if possible. Most of us use barbs and clamps to connect the tubing and they can leak too, slowly.

ALWAYS pressure test all components before going into service. I spaced out and let our 5bbl brites go into service with leaks all over the place. Gas connections, check valves, carb stones, quick connects, gauge threads, etc. Total nightmare. Luckily one tank was empty so it was pressure test, repair, test again, then clean, transfer and carb again. Then repeat three times. Embarrassing mistake to make. So give your new keg the full once over before you use it. Better to find a leak in an empty keg than when you're expecting delicious beer.

I did not pressure test anything before putting beer in it. I was given the keg and was told everything was ok so I just assumed....And then figured since when I pull the release valve pressure comes out I figured it was ok.

My new keg I have cleaned and sterilized and sitting on pressure right now. Sounds like I should get a spray bottle for Star San do some spraying and check my PSI.

 

[doug293cz]

Thanks for the in depth response! It looks like I should be purging upwards of 20 times with a set it and forget it of 12 psi!!! How often should I be purging to get the total number of purges I need - a few times a day? Once a day for a couple of weeks?

I guess my main question is then what is your psi and purge process for carbing up a beer in your kegs doug293cz? I would love to have a process down so my beer tastes as good out of the keg as it has been out of the bottles.

I would love to have someone write a "how-to for dummies" in regards to the set it and forget it with purging and when the beer is ready. There is a ton of different information out there about quick carbing, what to set your psi at for temp in fridge, etc.. But nothing like here DO THIS for perfectly carbed beer every time.

To purge the headspace of O2, all of the required purges should be done immediately after filling the keg, in order to minimize the amount of O2 that can diffuse into the beer. In addition, if the beer already has significant dissolved O2, it might be beneficial to do an additional headspace purge cycle every 12 hours or so for a couple of days, to help get rid of headspace O2 that diffused out of the beer. This would help more O2 diffuse out of the beer, further lowering the dissolved O2 content.

Personally, I do a liquid purge of the keg, followed by a closed transfer from the fermenter to the keg. Even then I do about 10 purge cycles at 30 psi to clear any residual O2 that might have sneaked in during the process. If I didn't do a closed transfer, I would do 13 - 14 purge cycles at 30 psi.

For carbing, I do a burst carb of either 24 psi for 48 hours, or 30 psi for 36 hours (others do 40 psi for 24 hours.) Then I vent the headspace, and reset the pressure to 12 psi. I cold crash, so my beer is at 32° - 34°F when kegged, and I carbonate and serve at 34° - 35°F. My beer is drinkable after 3 or 4 days, although it's usually better after a week.

Brew on

 

[VTX1300]

If you are doing 2.5 gallon batches maybe you should invest In a 2.5 or 3 gallon keg. I realize they are not cheap but that would take away a lot of head space issues. Half a keg of head space is a lot of wasted co2.

 

[wiggybrewer]

You say your serving in the mid 40s, try the mid 30s. and see if that helps.

 

[bucketheadmn]

If you are doing 2.5 gallon batches maybe you should invest In a 2.5 or 3 gallon keg. I realize they are not cheap but that would take away a lot of head space issues. Half a keg of head space is a lot of wasted co2.

I have been wondering about this. I started with normal 5 gallon kegs in case I ever decided to brew up a larger batch, though not sure I see it happening any time soon as my kettle is not large enough...

I might have to pick up a 2.5 gallon Torpedo Keg as they seem the most cost effective with good reviews. Been watching craigslist locally and the smaller ones never come up for sale.

 

[SanPancho]

I have been wondering about this. I started with normal 5 gallon kegs in case I ever decided to brew up a larger batch, though not sure I see it happening any time soon as my kettle is not large enough...

I might have to pick up a 2.5 gallon Torpedo Keg as they seem the most cost effective with good reviews. Been watching craigslist locally and the smaller ones never come up for sale.

ive got one for sale right now. not sure where you're located.

 

[bucketheadmn]

To purge the headspace of O2, all of the required purges should be done immediately after filling the keg, in order to minimize the amount of O2 that can diffuse into the beer. In addition, if the beer already has significant dissolved O2, it might be beneficial to do an additional headspace purge cycle every 12 hours or so for a couple of days, to help get rid of headspace O2 that diffused out of the beer. This would help more O2 diffuse out of the beer, further lowering the dissolved O2 content.

Personally, I do a liquid purge of the keg, followed by a closed transfer from the fermenter to the keg. Even then I do about 10 purge cycles at 30 psi to clear any residual O2 that might have sneaked in during the process. If I didn't do a closed transfer, I would do 13 - 14 purge cycles at 30 psi.

For carbing, I do a burst carb of either 24 psi for 48 hours, or 30 psi for 36 hours (others do 40 psi for 24 hours.) Then I vent the headspace, and reset the pressure to 12 psi. I cold crash, so my beer is at 32° - 34°F when kegged, and I carbonate and serve at 34° - 35°F. My beer is drinkable after 3 or 4 days, although it's usually better after a week.

Brew on

Well 2.5 weeks after putting it in the keg and it is carbonated perfectly. Patience is key it seems as with everything else.

I am brewing up Lil' Sparky's Nut Brown Ale tonight and that is the next that will hit a keg in a few weeks and I will be trying your method to speed it up just a little bit.