Lawrence Brewers Guild

I have a question about kegging from what i found you can pressurize a keg to 30PSI and roll the keg to get the CO2 all around the beer, however i am not sure how long it should stay at 30 psi after you get done rolling it.

I assume it maybe a day or so but i am not sure.

Thanks guys

First I ask do you have to have this keg ready in just a few days (less then 2 weeks)? As your question points out there is no clear answer or science to this method of carbonation. Every brewer that uses it has found some system that works and continues to do so. The problem comes when you try to figure out how much CO2 has been dissolved by the agitation of the liquid. I have read about brewers that will achieve "carbed" beer in a little more then a day but then can't figure out why their dispensing system spits out foam on the first pour after it has sat for as short as a couple hours.

I prefer the "Set it and forget it" method. This is where you find the ideal carb level you want and based on your holding temperature get an accurate CO2 pressure to carb your beer. This method is infinitely repeatable with the same results every time as there are no variables. It does take some time 2-3 weeks depending, (some beers can be served in a little over a week).

While I haven't actually answered your question I recommend taking the time to "set it and forget it" if you have the time. If you don't have the time I would try the following method: rocking/rolling a cold keg at 30 psi until you hear the CO2 stop going into the keg (it sounds like pings inside), dropping the CO2 to the "set and forget" PSI. Then for the next couple days giving it a shake. Finally taking a sample after a few days to see how you've done.

I've never tried force-carbing, but I've heard that a keg can be carbed in an hour or two with 30PSI and fairly constant agitation. I've also heard that the result will be large bubbles that quickly leave the glass. If you're in a hurry, I guess it's an option.

There is a good chart on carbing and how to get the proper volumes of CO2 dissolved in your beer. Thanks, Chris! (Try the "search" function! Type in "carb chart".)

I use 18-20PSI for 36-48 hours (depends on the beer) at 36 degrees (F), top-down (through the gas tube). Then I disconnect the gas. I think it gets better after sitting a few more days, but if the keg has been cold-crashing for over two days, the sediment comes out in the first quarter of a pint. I toss it, and the beer is usually ready to drink two days after kegging.

Other people swear by bottom-up (in through the liquid tube) to increase surface area exposed to gas. If you do this, **make sure you change the fitting to a liquid fitting** and do not just cram the gas fitting onto the liquid post!!

Carbonation can be fine-tuned to your serving system, habits, and personal preference. I have a primitive method (picnic taps, no manifold): serve until I'm done for the day or until the keg won't serve, then put 10-15PSI on the keg and remove the gas line. It'll be ready to push beer the next time you want one, and the beer will not go flat while it fills the keg with CO2 coming out of solution. Too foamy? Pull the release valve and wait a while (you'll lose aromatics each time you do this; after my beer is carbed I like to err on the low-pressure side). Not fizzy enough? Re-connect the gas and wait a while.

I'm pretty new to this so I well remember how much all this new info sounds intimidating. But by the time you've kegged and served two kegs of beer, you'll be an expert! (At least expert enough to get the beer back out!) Patience is your friend. RDWHAHB.

Unless you enjoy carbonic acid don't do the roll and carb deal. But hey, to each of their own.

Thanks for the input a I'm on day 2 of set it and forget it.

jl72189 wrote:Thanks for the input a I'm on day 2 of set it and forget it.

The only way to carb. Just remember, time, temp, and pressure is where it all happens. And all of these factors rely upon each other.
Im a bottoms up, 20psi, 36 hr, 38* carb kinda guy.

Steve Brown wrote:I've never tried force-carbing, but I've heard that a keg can be carbed in an hour or two with 30PSI and fairly constant agitation. I've also heard that the result will be large bubbles that quickly leave the glass.

The only difference in the results from different carbing techniques is in how long it takes to get to a given level of saturation. Once the CO2 is in the beer, it's all the same, and how it got there is lost to history. The technique has no effect on the finished product. Forced carbing cannot result in bigger bubbles than slow carbing (unless you forget to back it down to serving pressure).

JL, Andy mentioned temperature in passing. Let me emphasize how important temperature is to the speed and capacity of saturation. The colder the beer is, the faster it will carbonate and the more CO2 it will hold.

Another consideration is surface area. The larger the surface of the beer exposed to the CO2, the faster the gas will carbonate in the beer. The surface area of the beer in a keg laid on its side will be larger than a keg held upright, especially if it is not full.

I assume that you're in a hurry to carb the beer because you're in a hurry to taste the beer. I've been there and done that. I forced carbed my first few kegs too. I found that sitting down, laying the keg on my knees, and alternating raising one knee at a time would violently slosh the beer around with a manageable amount of exertion. Or, you can throw it in your trunk and take a drive off-road!

I suspect that you will quickly learn, as I did, that your beer will look and taste better after it has had a chance to cold-crash and lose that last bit of acetaldehyde and diacetyl. Don't drink it all before it's had a chance to taste good.