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norciabrewmonk
04-12-2014, 05:59 AM
So, we've recently increased our brewhouse and fermentor sizes, but our bottling line is the same. Now our bottling time will go from 2.5 hours to possibly between 6-10 hours. We keep our bottling tank (a fermentor) around 1 bar to push the beer to the bottling machine. I know over time the beer will begin to pick up CO2. I'm assuming every so often I would need to de-pressurize the tank, re-mix it, and re-pressurize. I guess my question is how often should I do this? After every two hours, every three hours, four ?
I know there's also the problem of the yeast settling out over time too, which is why I re-mix by putting CO2 up through the bottom.

Any thoughts or experience?

Unfortunately, a bigger or faster bottling machine is out of the question for awhile.

gitchegumee
04-12-2014, 02:18 PM
If your beer is carbonated to reasonable levels, then you will NOT PICK UP any CO2. Look at a saturation table. If you hold your tank at 1 bar and 5C, then your beer will stay carbonated at 2.65 volumes forever. I would not "remix" or blow CO2 through the bottom. All this does is foam your beer and cause head formation issues later. If you want to keep a certain amount of yeast suspended, then either install a mixing paddle, or recirculate very, very gently. And congratulation to the Italians for winning many medals at the WBC! Salute!

norciabrewmonk
04-13-2014, 01:53 AM
If your beer is carbonated to reasonable levels, then you will NOT PICK UP any CO2. Look at a saturation table. If you hold your tank at 1 bar and 5C, then your beer will stay carbonated at 2.65 volumes forever. I would not "remix" or blow CO2 through the bottom. All this does is foam your beer and cause head formation issues later. If you want to keep a certain amount of yeast suspended, then either install a mixing paddle, or recirculate very, very gently. And congratulation to the Italians for winning many medals at the WBC! Salute!
I guess that's where my dilemma is. The beer is "flat" and unpressurized before we bottle (taking into account the CO2 of the beer at around 2 C, but unpressurized). We re-ferment in the bottle, so our calculations have been based on the unpressurized CO2 amount.
I guess one option would be to pressurize it to 1 bar overnight, and calculate for the remaining CO2 amount by yeast fermentation.
Although I guess another question would be how much would that affect the quality. We definitely want the benefits of re-fermentation rather than forced carbonation.

ColdFusion
04-13-2014, 05:02 AM
Perhaps you could consider using nitrogen instead of CO2.

gitchegumee
04-13-2014, 07:58 AM
Had no idea you were bottling with low CO2 and bottle conditioning. That's a whole other story! Nitrogen is a great idea. Better than pumping if you're already using head pressure to bottle. Inexpensive and relatively easy, too. I think ColdFusion found your answer.

norciabrewmonk
04-14-2014, 09:36 AM
Had no idea you were bottling with low CO2 and bottle conditioning. That's a whole other story! Nitrogen is a great idea. Better than pumping if you're already using head pressure to bottle. Inexpensive and relatively easy, too. I think ColdFusion found your answer.
So, this is obviously different from carbonating with nitrogen?
Mainly that I would not have much CO2 loss or pick up if I used nitrogen to push the beer to the bottler?
And would it still be cheaper if I'm using 50 lb tanks instead of using a nitrogen generator?

ColdFusion
04-14-2014, 02:13 PM
So, this is obviously different from carbonating with nitrogen?
Mainly that I would not have much CO2 loss or pick up if I used nitrogen to push the beer to the bottler?
And would it still be cheaper if I'm using 50 lb tanks instead of using a nitrogen generator?

IIRC nitrogen has something like 100x lower solubility in water/beer than CO2. You won't have to worry about N2 affecting the beer over the course of your run, either by dissolution or displacing dissolved CO2; if you simply add N2 to the headspace, your partial pressure of CO2 will remain the same unless i'm overlooking something. Your cost of pushing with N2 will likely be lower than using CO2.

TL Services
04-14-2014, 11:43 PM
Hi,

Using nitrogen to push the beer to your bottler would be fine and yes, very probably cheaper than CO2!

Also, if you need to keep yeast in suspension rather than settling in the tank, nitrogen would be okay for this as well.

You may find that a a small amount of nitrogen dissolves in the beer, but this would not be a problem; indeed, it can improve the head as it gives smaller, tighter, bubbles than CO2.

norciabrewmonk
04-23-2014, 10:07 AM
Would anyone have any idea how much more N2 I would need compared to CO2 at least using tanks?

Ted Briggs
04-24-2014, 07:14 AM
The best solution would be to pump it and keep a low head preassure on the tank. N2 will be a good work-around till you can afford a pump.

http://www.spx.com/en/waukesha-cherry-burrell/pc-pumps/

TGTimm
04-24-2014, 09:21 AM
Would anyone have any idea how much more N2 I would need compared to CO2 at least using tanks?

You'll need the partial pressure of the CO2 to equal the breaking pressure of your beer at your altitude and bottling temperature. The breaking pressure can be found on a P/T chart; unless you're at a very high elevation, don't worry about that.

The total pressure of the mixed gas will be your push pressure. So, the pressure of the CO2 (breaking pressure) + pressure of nitrogen = push pressure. If your breaking pressure is 5 psi, and you want a push pressure of 15 psi, you'll need 10 psi of nitrogen and 5 of CO2.

There are many automatic gas mixing valves on the market, some set and some adjustable. Call your bar equipment supplier for info on these.

TGTimm
05-22-2014, 02:00 PM
Oops, sorry. I answered the wrong question.

1 lb of CO2 produces 8.74 cuft of gas at STP. 1 lb of nitrogen produces 13.89 cuft at STP, so your nitrogen usage would be far less than your CO2 usage.