Anyone ever thought of trying to use CO2 from the same batch to bottle that batch?

[iandanielursino]

If the CO2 is captured in a keg at 12PSI I'm guessing that will not be enough pressure to bottle 5-10 gallons of beer sitting in the fermenter after lagering at 8 PSI (example for the sake of illustration).

I wonder if there is any kind of an air compressor that could be hooked to a little keg that receives CO2 from your fermenter through a one way valve and periodically pumps it into another keg which you use as the pressure source to run a beer gun.

The Blichmann beer gun's manual specifies 15-20 PSI for the CO2 input for the purging function, but I wonder how many PSI minimum needs to be in the tank for it to supply 15 PSI to a regulator. Of course at the same time we would have to supply 8 PSI (in the arbitrary example) to the fermenter to keep it topped off.

Another thought would be to run a beer gun from a pump instead of regulating the fermenter, that way you only need CO2 to purge with, or trying to do it without a regulator, last time I racked at like 3 PSI into a bottling bucket it sorta felt like the pump was unnecessary (Spike CF10 with racking arm). Even then, if you set your PRV to 12-15 PSI and therefore got about that much in your keg I sorta have doubts about whether that would be good for purging.

If the CO2 is from the same batch it shouldn't mess with your flavor right? Or would it "go bad"?

 

[hotbeer]

One other consideration. The CO2 from your fermentation isn't just CO2. It is carrying away other things with it. Among them are substances that impart undesirable flavor and aroma notes.

I don't know what their life is or whether they'd condense out soon after being compressed or what.

 

[iandanielursino]

One other consideration. The CO2 from your fermentation isn't just CO2. It is carrying away other things with it. Among them are substances that impart undesirable flavor and aroma notes.

I don't know what their life is or whether they'd condense out soon after being compressed or what.

True, but would that be an issue for purging headspace but NOT an issue for pressure fermentation or natural carbonation?

 

[mac_1103]

You may enjoy this thread. Then again, you may not.

 

[iandanielursino]

You may enjoy this thread. Then again, you may not.

I skimmed that one, it seems interesting but I don't share the passion for complex solutions.

My irrational desire is for the system to work even if theoretically there was no CO2 supply and/or save money without making it function worse.

This thread seems more relevant: https://www.homebrewtalk.com/threads/use-a-keg-as-a-co2-vessel.698904 but, isn't beer usually fermented at 15 PSI or lower? That's all my tank is good for. That thread seemed to conclude that using captured CO2 for purging should be fine.

It seems that I would have to ferment something else in the keg in order to generate the CO2 in my scenario. Seems very viable in an "apocalypse" type scenario to put something fermentable in the keg just to generate CO2 I suppose. Or just rack and minimally prime already carbonated beer, I've thought about experimenting with that. Just using a normal CO2 source seems preferable to both though.

I suspect the real "apocalypse" option is to just serve the beer out of the tank and deal with the pressure changing over time, or treat the tank like a cask and prime it, or just make cask conditioned beer.

I can also imagine just lining up a lot of kegs in a daisy chain to simply raise the "headspace" volume so that the pressure drop as you dispense beer is less.

 

[sibelman]

he real "apocalypse" option

Bottling is also a fine choice in the absence of store-bought or captured/compressed CO2

In apocalyptic times, bigger supply issues (malt, hops, water!, energy!!) could complicate brewing.

 

[iandanielursino]

Yeah I've been priming so far, I don't have a kegerator or a place to put it yet and quite like bottles, so I'm planning to just use CO2 to bottle as my next upgrade. Fermenting with pressure makes it awkward to prime and fermenting without pressure makes it awkward to cold crash, and in either case its nice to not expose your beer to air.

The "crazy" comes into my thinking when I consider, well, can't I have some kind of a closed loop system that would work with that kind of improved process? The two downsides of priming being potential for oxygen exposure (unless you pipette prime the bottles), and pressurized cold crashing changing your calculations.

But yes, I also don't have a huge solar array that I would need to operate my all electric brewery, so I'd have to do it off propane with the generator, not a very serious proposition I think, so no not really a "prepper" idea.

I do wonder how big breweries do bottle conditioning, I imagine they individually prime the bottles so that the beer goes directly from the tank to the bottle at least.

Wouldn't it be neat though if you could install a little electric pump in the top of a corny, plug the corny into your pressure fermenter with a one way valve, set the PRV on your fermenter, and then have it gradually fill up a tank?

 

[tracer bullet]

Or just rack and minimally prime already carbonated beer

If you have a fermenter that can handle the pressure, it does seem like a winner. Set it to 12 or some psi and have the beer carbonate itself. Afterwards stick it in the bottles. I've found that if you have a tube attached to a picnic tap, and VERY little head pressure in the keg, you can do a pretty good job with very little foam.

 

[iandanielursino]

I recently had the fermenter at 3 PSI because the pressureworthiness had failed (I since seem to have fixed that) so it didn't get up to my desired cold crash pressure. I set it up to rack using a pump, but it came out quite forcefully, I wonder if you even need a pump to simply dispense a tank through the racking arm that is at say 8 PSI after 3 weeks of lagering. I think I'll try next time. I don't have a volumetric pipette though so I may still need to use the ole' bottling bucket. The batch after that perhaps I will have simply purchased a CO2 tank and a beer gun.

I guess if I hook up my filling straw to the racking port and position it lower than the tank gravity siphon should finish it off regardless (and indeed the pressure may be too much for the filler and need to be dumped first)

 

[mac_1103]

Fermenting with pressure makes it awkward to prime and fermenting without pressure makes it awkward to cold crash, and in either case its nice to not expose your beer to air.

There are plenty of simple solutions to prevent air exposure when cold crashing without pressure fermenting.

Any container that will seal airtight can be purged with fermentation gas. Gravity closed transfers are a piece of cake.

 

[hotbeer]

True, but would that be an issue for purging headspace but NOT an issue for pressure fermentation or natural carbonation?

I'd think it be an issue for carbonation since you are putting possibly impure CO2 back into solution.

For clearing headspace of air and O2, not so much an issue since it won't be as much and most of the CO2 will be displaced out of the container by the beer or wort being put in it.

 

[iandanielursino]

I'd think it be an issue for carbonation since you are putting possibly impure CO2 back into solution.

Certainly, but provided the CO2 is from the same batch, would anything be different from simply spund carbonating? I.e.. is there a hazard in removing it from the fermenter.

 

[hotbeer]

Certainly, but provided the CO2 is from the same batch, would anything be different from simply spund carbonating? I.e.. is there a hazard in removing it from the fermenter.

If you are going to save all the CO2 that comes from fermenting and use it to carbonate, then it's going to be a lot more CO2 than what is retained by the little bit of pressure I've read that most pressure ferment at. Spunding doesn't carbonate the beer to the 2.5 - 3 vols we usually shoot for.

Our taster and smeller can perceive some impurities at very miniscule amounts. That's why in the beverage industry, there is a difference between food grade CO2 and beverage grade CO2. Beverage grade being much purer CO2.

As I said initially, I don't know how much of a concern it is for CO2 being gassed off from fermentation. But I know, or at least have read, that it does carry off some of the off tastes and aromas we rather not have in our beer. I have no idea if it precipitates out or decomposes to substances that aren't a issue.

 

[iandanielursino]

There are plenty of simple solutions to prevent air exposure when cold crashing without pressure fermenting.

I wouldn't say there are any that are as simple as simply ensuring (whether by spund fermenting or using a gas post) that there is pressure in the vessel before lowering the temp, and in any case when bottling the only options are gravity filling, pressure filling, or racking to a bucket using a pump. The most convenient of those is pressure filling and this harmonizes quite well with pressurized cold crash. (pressurized fermentation optional).

If you are going to save all the CO2 that comes from fermenting and use it to carbonate, then it's going to be a lot more CO2 than what is retained by the little bit of pressure I've read that most pressure ferment at. Spunding doesn't carbonate the beer to the 2.5 - 3 vols we usually shoot for.

It can at cold crash temperatures. If you were to lager at 8 PSI and 33 F for three weeks you would arrive at 2.41 volumes which is dead on for a German Pils.

As I said initially, I don't know how much of a concern it is for CO2 being gassed off from fermentation. But I know, or at least have read, that it does carry off some of the off tastes and aromas we rather not have in our beer. I have no idea if it precipitates out or decomposes to substances that aren't a issue.

Provided that we reach the same volume of CO2, it wouldn't matter if it was by forced carb or spund carb I think, because the same amount of CO2 from the same source has dissolved.

Here-again, unless it's the case that the CO2 changed by going out of the tank and into the keg.

I would agree that it would probably be bad to hook up fermentation gas to a regulator and use it to run a keg for weeks and weeks though. That way you're putting more and more in to backfill as the liquid is diminished. There does not seem to be much risk of that however as we haven't come up with a way to greatly pressurize it.

I've never heard anyone argue that natural carb tastes WORSE than forced carb, I could totally see that being a thing though as the forced carb would have less of the impure CO2 in solution (assuming whatever things we don't like go into solution that is).