Reclaiming CO2?

[TipsySaint]

So this post is just to see if i have in any way a working hypothesis.

From what I know about carbonating beers in kegs, the best way is to allow the CO2 to bubble through the beer. However, in order to do this and just get a beer carbonated quickly a lot of CO2 is wasted. Towards that end I was thinking, if I were to put a full CO2 tank on the dip tube and an empty CO2 tank (with appropriate filling device) on the gas out tube, maybe I could reharvest my leftover CO2? Maybe I could even chain together a few kegs for the process......

My fears are contamination of the CO2 with air and with beer particulates, possibly causing some sort of scary coating in the empty CO2 tank.

Anyone tried anything like this? Anyone know why/if it's a good/bad idea?

Thanks!

 

[KeystoneHomebrew]

You are creating, in short, a large leak with an outlet of a CO2 tank to catch it. Breweries that have CO2 reclaiming devices from fermentation like in Germany, still carbonate the beer using stones but no second reclaimer, if that makes sense.

Also, tanks are filled high pressure to high pressure (very cold conditions during this process keeps the gas liquid). I would worry about exceeding the limits of the CO2 tank and creating a burst. I honestly do not know if that is possible, but I would seriously take that into account.

I'm geeking out on this wondering, but I would approach it carefully.

 

[TipsySaint]

There would need to be a scale, a blow off valve, ball valve. The cold temps make sense. Perhaps it could all be done inside a freezer?

As far as reclaim from fermentation, that makes sense, not sure why they don't try to reclaim from the bright tanks....

 

[theredben]

How is any C02 wasted during carbonation? It is a sealed container, the gas isn't going anywhere other than into solution in the beer.

 

[BigFloyd]

How is any C02 wasted during carbonation? It is a sealed container, the gas isn't going anywhere other than into solution in the beer.

That's exactly what I was thinking when I read the original post. You're sending CO2 into a sealed keg at a set pressure and temp. The CO2 first accumulates in the headspace of the keg and then slowly over time (depending on the psi and temp) dissolves into the beer. As that happens, more CO2 comes through the reg/line into the keg to replace that which has now taken up residence in the beer where it belongs.

Unless you have a leak, you're not wasting anything.

I suspect that European breweries are now required to have CO2 reclamation devices over their fermentations because the EU has fallen for that whole man-made global warming nonsense.

 

[ResumeMan]

Yeah I think you are going wrong with this sentence:

...the best way is to allow the CO2 to bubble through the beer...

You're not letting it bubble through the beer. As was said by others, you seal up the keg and hook up the CO2 to it, that lets the gas dissolve in the liquid. You keep it sealed at all times after that. So there's really no gas being wasted.

 

[Paps]

As mentioned previously CO2 isn't really wasted force carbing a brew.
I have wondered how a homebrewer might attach something to their airlock to harvest CO2 during primary fermentation though to re-use in force carbing.

 

[DrunkleJon]

The only wasted CO2 would be the CO2 you vent out of the keg if you do the shake-and-bake method then vent and put back on pressure. If you go set and forget the only CO2 'wasted' is the CO2 you vent to the atmosphere after the keg is kicked. Now, if you could find a way to use the pressure left in the now empty keg for other uses.

Not to hijack, but I wonder if/how well venting this pressure through the gas in would work for transferring beer from a cold crashing/conditioning keg to a fresh one would work.

 

[TipsySaint]

Drunkle, you've pretty much got the idea. It's a bit of a high bred. If I put CO2 on the dip tube and vent pressure, this should cause the CO2 to dissolve into solution faster. If I were to vent the pressure back into another CO2 bottle, I would get the fast pass through of the CO2 and limit my loss to the ether. Set it and forget it works, but it works slow. I'm looking at a controlled version of the shake and bake,if you will.

 

[b-boy]

Drunkle, you've pretty much got the idea. It's a bit of a high bred. If I put CO2 on the dip tube and vent pressure, this should cause the CO2 to dissolve into solution faster. If I were to vent the pressure back into another CO2 bottle, I would get the fast pass through of the CO2 and limit my loss to the ether. Set it and forget it works, but it works slow. I'm looking at a controlled version of the shake and bake,if you will.

There's always the shake method... It's just a faster version of set and forget.

 

[BigFloyd]

There's always the shake method... It's just a faster version of set and forget.

"Burst carbing" is the faster version of set/forget and need not involve any shaking.

I tried the shake method one time and will not do it again. That Northern English Brown stayed cloudy until the day it kicked.

 

[JuanMoore]

I use a carb stone for those rare occasions I need to carb super fast. Chill to serving temp, set gas to 1-2 psi, turn up pressure 1-2 psi every hour or two until it's at serving pressure.

 

[TipsySaint]

Bigfloyd what do you mean be burst carbing?

 

[DrunkleJon]

I still would be wary releasing any CO2 to the atmosphere in hopes of carbing faster. You would be pushing off the wonderful aroma with your venting. If the set and forget (usually quite good in a week) is not an option the burst is probably your best bet. After that if you are really in a rush, the shake and bake may be your best bet and with all three you waste less CO2.

My thoughts are that reclaiming the CO2 may not really be worth it. If you can get reasonably priced swaps/refills the risk of any contamination, be it flavor/roma or worst case an infection would be far more expensive than the small amount of reclaimed CO2

Just my 2 cents.

 

[kombat]

If I put CO2 on the dip tube and vent pressure, this should cause the CO2 to dissolve into solution faster.

No it won't. The way to get CO2 into solution is by applying pressure. If you're venting pressure, then the CO2 will go out the vent rather than dissolve into solution.

As others have said, as long as you do not have a leak in your keg, then no CO2 will be "wasted." It will go into solution. There are ways to accelerate the process, such as chilling the beer as close to freezing as possible, increasing the CO2 pressure, and shaking the beer. But venting pressure will just waste CO2.

Also, if you do decide to actually go ahead with this foolish idea, make sure you use the proper quick disconnect fitting. You will need to construct a CO2 supply line with a liquid quick disconnect fitting instead of the usual gas disconnect fitting. If you connect your gas disconnect fitting to the "liquid out" post of your ball lock corny keg, you will have a heck of a time trying to disconnect it later.

 

[BigFloyd]

Bigfloyd what do you mean be burst carbing?

Burst carbing is where you chill the keg to below 40*F, hook up CO2, hit it with 30psi for a day or so and then drop it either to 20psi a couple of days or straight down to service pressure.

Unless there's a specific reason to rush it along, I prefer to just set at 11-12psi and leave it alone for a couple of weeks.

 

[TipsySaint]

So I've been carbing for a few years at this point. Fairly familiar with all these techniques. Further tease arch has yielded the fact that when you transfer co2 from tank to tank it needs to be n it's liquid state. I was considering transferring its gas state. I know it's about pressure and surface area, so the idea of a constant co2 bubble through the beer and then harvesting the co2 seemed attractive. It seems this cannot be done. So bye bye project.

 

[JuanMoore]

So I've been carbing for a few years at this point. Fairly familiar with all these techniques. Further tease arch has yielded the fact that when you transfer co2 from tank to tank it needs to be n it's liquid state. I was considering transferring its gas state. I know it's about pressure and surface area, so the idea of a constant co2 bubble through the beer and then harvesting the co2 seemed attractive. It seems this cannot be done. So bye bye project.

For the bubbling through technique to be effective you need to be using tiny bubbles of CO2, like you get with a carb stone. Many brewers accelerate the carbonation process this way. You don't really let a whole lot of CO2 escape if you're doing it right though, so it doesn't make much sense to attempt collecting it. There's also the issue that it causes you to lose some of the hop aromatics that are so cherished in hop forward beers. A carb stone will greatly accelerate the carbonation even without letting it vent. It only takes ~12 hours using the method I described earlier.