Hi all! I’m new to brewing and seem to be having trouble with carbonating my Sanke kegs. I’ve got 3bbl system so I’m running more beer than a home brewer but still brewing on a small scale. I currently have 8 5gal Sankes of American Pale Ale force carbonating with 23 psi at 55 degrees. I took the kegs off carbonation at 5 days and moved one of them to my kegorator that’s running between 38-40 degrees. I’ve got my serving psi set at 15. My problem is the kegs have very low carbonation. Everything I’ve read seems to indicate that the carbonation should be more prevalent at 23psi for 5 days. I’ve tested all my lines for leaks and haven’t found any. Is there something I’m missing or doing wrong as a newbie?! Thanks in advance for any insight!
Probably better suited to the home brewing forum, but maybe some of the folks over there watch here too.
I recommend against high pressure force carbing for now. It can be hit and miss, even experienced brewers will be cautious because the time/temp/pressure is not always what you want it to be. At 55 degrees you ain't carbonating much of anything. That is too warm. Sure, the carb chart will give you v/v at some psi at 55 F, and it is physics, but it just does not work out that way. Set your regulator to 10 psi. Keep your beer at 38 (38, not 40 or 42 but 38). Let is sit for 5 days and see how it is. Cheers
Thanks for the advice! For some reason I can’t seem to figure out how to get it over to the home brewing section. Feeling like a bit of an idiot, ha. I’m new to interacting within forums.
Thanks for the advice...I had my concerns with carbonating at that temp but it’s the space I’ve got at the moment. I’ll have to get that fixed.
Not to start an argument, but it exactly works out that way. Regardless of how it's carbed, it needs to be at 38F-ish before pouring. If you carb it at 55F, then try to pour it without chilling it first, it will appear to be badly overcarbed, which can be a source of confusion. Overnight in the chill chest should be adequate. 24 hours is even better.
Thank you. I’ve read of people carbonating warm and I would think 55 degrees would be considered “warm.” Maybe the problem I’m having is not getting the keg chilled down well enough before I start pouring, like you stated. I’ll give that a try. Do you think 5 days of carbonation at 55 degrees and 23 psi is long enough to get adaquite carbonation??
Good point on chilling the beer before testing but it seems they are being chilled before serving and they're still coming up under-carbonated - unless I misread the OP. Force carbonation is actually a little more complicated than it appears because there are other laws of physics in play. Time, temperature and pressure are the main components, but time can be affected in many ways including the way it's carbonated. @Ramblinrose, have you been shaking that keg every once in a while? That helps. The lower the temperature the better, but the actual volume of beer that is in contact with the gas makes a huge difference as well. You should always leave yourself a few inches. And is your gas going in the "in"? If not the stem could be holding you back. And personally I don't see why you would bother to try to carb it at 55F except that you don't have the space in the fridge. One at at time at 38-40F will get you there a lot quicker than 55F - or just wait. Additionally, as an aside, the weight of the C02 itself can also come into play when we're talking about large vessels of some height - but that of course is for professionals to deal with, not homebrewers. Good luck.
Maybe. Maybe not. (I'm going with maybe not) 55F at 23psi will equilibriate to about 2.55 volumes on the chart I'm looking at, probably right about where you want to be. There are a lot of variables that will affect the time, but 5 days is optimistic, in my experience. I usually allow 10 days, give or take, unless I'm in a hurry. Temperature is irrelevant, as long as you use the charts.
Thanks for the reply. I have not been shaking the kegs at all but it’s certainly something I could try. I have made sure to leave some space in the keg and my gas is going in the “in”. The reason I’m carbonating at 55 degrees is bc this is the only area I have to carbonate. My kegorator is tied up with kegs throughout the week and weekend with beer that’s ready to be served.
I have been kegging since I started brewing and have never bottled except for the leftovers. 5 days with no shaking of the keg to full carbonation is pushing it. I use ball lock kegs and can stick my gas on the out post forcing the gas through the beer. Doing it this way I can usually get my beer to full carbonation at serving pressure in about 6 to 10 days. But doing it this way has some advantages, each bubble of gas going into the keg comes in contact with more beer and the upward movement of the bubble causes the contents if the keg to be "stirred". This causes more beer to come in contact with the pocket of gas at the top of the keg allowing for more absorption of co2.
Unfortunately that is not quite how the gas is dissolved into liquid. In equilibrium there are no bubbles. That is equilibrium. And as the beer absorbs gas the pressure is going into the liquid, not escaping. Once it reaches equilibrium there is no gas exchange. The bubbles are caused by gas moving from dissolved in liquid to escaping into atmosphere, and that is a function of applied pressure, with nucleation points offering a catalyst for bubbles. There is no keg stirring from applying CO2 gas to a keg. Cheers.
You are right to a point, but since the gas at the top of the keg is also being absorbed by the the liquid equilibrium is never reached until the full volume of gas able to be absorbed by the liquid is reached based on pressure and temperature. Since this is the case there are constantly small bubbles of CO2 being released into the bottom of the keg. The upward motion of the these bubbles causes more movement than the natural currents found in a liquid. Plus the added absorption of gas from the sphere of gas (as defined by flicks law) as it moves to the top of the keg. You can increase the absorption rate by decreasing the size of the spheres of gas by installing a bubbler on the end of the tube. Which in my opinion is more work than it is worth. Here is the formula to figure out the absorption rate of a column of gas bubbles (CO2) in a column of water. d(w ∞ρ1) AL--------------------- =m g0n= dr =4πr0D gρ1 (w0-w∞) 27v1Lmg ----------------- 5 8πgρgr 0 dw∞ 27v1DgUg -> ------------- = ------------------------- (Wo-W∞) 4 dt 2gr 0 Not perfect but close. A lot of it is out of position but you can get the general idea, If you are nerdy like me. This formula I found a few years ago trying to find the easiest way to carbonate beer without having to shake it or anything because at the time I couldn't even lift a 5 gallon keg. This formula actually came from a research project involved in getting rid of CO2 on submarines. The process is effective and cuts 4-7 days off of the force carbonation process at serving pressure and cuts off more if you up the pressure, which I have only done once.
Another way to increase absorption rate of CO2 with out doing anything is to lay the keg on its side. This increases the gas / liquid contact surface area. I personally don't like this because you increase the chance of getting beer up your gas line. But does take a couple of days off your carbonation time.
