Dispensing Without CO2 Bottle

[fifis101]

So my brother is wanting to get away from bottling but isn't quite ready to commit to the full cost of a kegerator and CO2 etc. He is looking at getting a pressure fermentor though. He was in the brew shop the other day having a discussion on option and the attendant told him that if you brew under pressure, you should have no issues dispensing straight from the fermentor without a CO2 source. I agree with that to an extent. You will start off with well carbonated beer but as you draw down on the beer, the pressure is going to go down and the beer become less carbonated right?

To counteract this I suggested he could pressurise some of those 8L PET bottles during the fermentation and use that to aid in keeping up the pressure.

Keen to start a discussionon this sort of thing. Basically along the lines of being self sufficient on CO2.

 

[fifis101]

Does anyone have anything on this subject?

I'd be surprised if no one has ever tried to capture their own CO2 and reuse it.

 

[Half-baked]

Depends on how low he’s happy for the carbonation to get towards the end or how quickly he’ll drink it.

Let’s say he’ll drink slowly and wants a reasonable amount of carbonation. He’ll need an excess of 4.5g/l of co2 to dispense a 19l keg. That’s 85g of excess CO2, on top of 4.5g/l needed in the co2 storage tank/s. So he’ll need to capture 85l of co2 stored at 5.5g/l to be able to dispense at 4.5g/l (around 2.3 vols).

Unless my logic is flawed (which it very possibly is) that doesn’t sound very practical…

 

[wide eyed and legless]

So my brother is wanting to get away from bottling but isn't quite ready to commit to the full cost of a kegerator and CO2 etc. He is looking at getting a pressure fermentor though. He was in the brew shop the other day having a discussion on option and the attendant told him that if you brew under pressure, you should have no issues dispensing straight from the fermentor without a CO2 source. I agree with that to an extent. You will start off with well carbonated beer but as you draw down on the beer, the pressure is going to go down and the beer become less carbonated right?

To counteract this I suggested he could pressurise some of those 8L PET bottles during the fermentation and use that to aid in keeping up the pressure.

Keen to start a discussionon this sort of thing. Basically along the lines of being self sufficient on CO2.

It has been discussed before, can't recall the thread probably in the pressure fermenting thread. Yes you can capture the co2 but how does one then pressurise it? My first thought was using water pressure. Where gas is easy to pressurise liquid isn't so obliging, the downside being water carries oxygen and gas will dissolve into the water.
The only real answer is the bladder in the keg. Then co2 will not be needed, only air, a picnic pump, a bicycle pump or a small electric air pump. Put pressure on the bladder the carbed beer in the bladder will pour.
I did ferment in a cube once an English bitter, I did a gravity pour from the cube, while it was clear and easy to drink it was lacking in the contribution from the yeast. I did drink it fairly quickly and the carbonation did last. This was 2017

I did test the cubes for pressure to 26 PSI, as you can see it made them a funny shape.

The cube on the left held captured co2 with the gravity pour from the cube.

A reasonably clear beer, an easy drinking beer but just doesn't cut it taste wise. Pressure isn't the way to go for ales. The bladder is the best solution if not wanting to purchase co2.

 

[mynameisrodney]

If you want to minimise the change in pressure over the course of the dispense, using a larger fermenter (or using a smaller batch volume) will also help.

EDIT: I should mention though, if he's planning to go the unitank option anyway, the cost of buying a CO2 cyl and a regulator is so cheap these days its really not worth the hassle of mucking about trying to do CO2 capture. you're talking about an extra ~$120. You dont need to make a full kegerator/keezer.

 

[Ballaratguy]

A 23Lt ferment should be able to fill 4 19Lt Jed’s to about 20 psi

 

[Ballaratguy]

A 23Lt ferment should be able to fill 4 19Lt kegs to about 20 psi

 

[blacktop™]

EDIT: I should mention though, if he's planning to go the unitank option anyway, the cost of buying a CO2 cyl and a regulator is so cheap these days its really not worth the hassle of mucking about trying to do CO2 capture. you're talking about an extra ~$120. You dont need to make a full kegerator/keezer.

I totally agree with this. Not to mention having ultimate control with a regulator etc.

Although the concept of being self sufficient with co2 is kinda cool, I think the hassles far outweigh the benefits. It would literally be removing fun from the hobby.

 

[fifis101]

I totally agree with this. Not to mention having ultimate control with a regulator etc.

Although the concept of being self sufficient with co2 is kinda cool, I think the hassles far outweigh the benefits. It would literally be removing fun from the hobby.

I don't know about removing the fun. I personally don't see it being a hassle in any way. I already use my fermenting gas to purge my kegs & I pressure ferment & generally only use gas to dispense.
Imagine if you had a 45kg LPG bottle. I think the volume is 88L. That sitting there at 25psi & regulated down to 10-15psi to dispense. Topping it up every time you brew. It could be a simple way to be self sufficient.
Sometimes it's the challenge that makes it interesting.