Co2 racking from carboy to keg idea!

[nextgenxx]

So I am trying to make things easier... I had this idea to pressurize a carboy with co2 (no more than 3-5lbs) with an orange carboy cap. Then hook my racking cane up as the dip tube through the cap to pick the beer up and then have a line to transfer the beer to my beer-out line on the corny keg. I'm trying to limit as much oxygen as possible. I have read some of the closed pressurized fermentation system methods so I think this idea should work. Anybody have any thoughts if this is a good idea or not? Thanks!

See photo

 

[AlCophile]

I'd throw a blanket or other shrapnel-shield over that 'boy.

 

[SAMPLER]

Actually do it all the time but without the clamp. Also if you are transferring into a sealed keg via the out port make sure to keep the pressure relief valve on top open so you can force and air in the keg out as you fill.

Good luck

 

[nextgenxx]

So one person thinks it will explode, and another person does it all the time! 50/50 Chance! Lol

I did blow on the air side (don't make jokes) and plugged the racking cane with my thumb as a pressure test and did notice that just with my lung pressure there seemed to be good pressure relief when I removed my thumb.

I don't want the carboy to explode by any means that's why I said I wouldn't use more than 3-5lbs of co2. Should I go lower still?

 

[amandabab]

I do it, but disconnect the gas after it starts. the co2 blanket is there, and gravity will finish it.

 

[shelly_belly]

I do it without the clamp on the cap. When I get too aggressive with the CO2 the cap will blow off of the carboy.

 

[Pratzie]

disconnect the gas after it starts. the co2 blanket is there, and gravity will finish it.

This.

And make sure about the pressure relieve valve as mentioned above.

 

[nextgenxx]

This.

And make sure about the pressure relieve valve as mentioned above.

All these tips are great! Disconnect co2 after flow starts and keep relieve valve open as filled. In theory it all sounds good to me!

I kinda want to do a exploding test of a glass carboy now just to see what it can withstand. Does that sound strange?

 

[PrSlater]

Sounds like a job for mythbusters! I wouldn't want to risk the danger or expense of blowing up a glass carboy but that's just me. closed system transfer works well but make sure you purge the keg with CO2 or it will void your O2 exposure. the blanket of CO2 in the carboy makes for O2 exposure minimal when opening and racking but whatever you prefer. like I said tho purge the keg or all the effort of closed system will be all for not

 

[Tiber_Brew]

I've been using a similar method for about a year now (minus the clamp on the cap). Works great. I use a dedicated CO2 regulator at about 1-2 psi for the transfer. I also use plastic fermenters for this.

 

[IslandLizard]

I think this is a great idea, but make sure you don't exceed 2-3 psi. Not sure what pressure carboys are rated at, but I bet they won't take even 1 atmosphere (14.7 psi) of pressure difference (such as a vacuum). So no clamp!

You can't shut off the CO2 supply once the flow or siphon starts. You'll need to keep supplying CO2 to displace the same volume of beer flowing out.

I'm gonna be using your method next time I keg.

 

[IslandLizard]

Sounds like a job for mythbusters! I wouldn't want to risk the danger or expense of blowing up a glass carboy but that's just me. closed system transfer works well but make sure you purge the keg with CO2 or it will void your O2 exposure. the blanket of CO2 in the carboy makes for O2 exposure minimal when opening and racking but whatever you prefer. like I said tho purge the keg or all the effort of closed system will be all for not

How do you effectively purge the keg from air with CO2?
CO2 is somewhat heavier than air, but flowing it in, even with a tube on the bottom, will still mix largely.

Is a vacuum followed by a complete CO2 fill the "only" way?

 

[PrSlater]

CO2 in the keg will be heavier than O2 so just enough to blanket the bottom 1/3 or so of the keg will suffice. A vacuum is not necessary since the CO2 itself ( being heavier than O2) will sink to the bottom the the keg forcing out any oxygen above it. The air may be turbulent at first but the two will settle out, kind of like oil and water.

 

[AnOldUR]

Been doing this for years also, but always keep the gas on at a low pressure for the entire transfer. Probably doesn't make a lot of difference because of the short exposure time. Still, why take the chance? It's too easy and doesn't use that much gas if pressure is turned way down. Without the gas on, the air coming into the carboy will dilute and mix with the existing CO2 rather quickly if you disconnect. And I agree with the others about losing the hose clamp on the carboy cap. It's somewhat comforting to think that the carboy cap will blow off if the pressure accidently gets too high rather than exploding the glass. As for the keg, I purge and then cover with a Starsan soaked paper towel to limit gas transfer. I have used the "OUT" tube to transfer, but went back to a clear tube. Works the same and it's easier to get a hydro sample or to pull out when the keg is full and you want to put the last bit of beer into a PET bottle for carbonating.

The air may be turbulent at first but the two will settle out, kind of like oil and water.

If this was true, we'd all die on a calm day. Sorry, but gasses are not like oil and water.

.

 

[PrSlater]

If this was true, we'd all die on a calm day. Sorry, but gasses are not like oil and water.

.

I was just using this a over dramatic simile. but just for my own information I was under the impression that the heavier CO2 would sink to the bottom as it is heavier than O2... is this not the case?

 

[AnOldUR]

I was just using this a over dramatic simile. but just for my own information I was under the impression that the heavier CO2 would sink to the bottom as it is heavier than O2... is this not the case?

I'm a machinist, and don't claim to understand all the science, but what I've read leads me to believe that the blanketing effect of CO2 exists, but is only temporary. If the topic interests you, do a search on the diffusion of gases and let us know if you find anything new.

Diffusion often masks gravitational effects. For example, if a relatively dense gas (such as CO2, carbon dioxide) is introduced at the bottom of a vessel containing a less dense gas (such as H2, hydrogen gas), the dense gas will diffuse upward and the less dense gas will diffuse downward. It is true, however, that at equilibrium the two gases will not be uniformly mixed. There will be some variation in the density and composition of the gas mixture; at the top of the vessel the gas mixture will be slightly less concentrated, and there will be a slight preponderance of molecules of the less dense gas. These differences, which are due to gravity, are almost impossible to measure in the laboratory, although they interact with other factors in determining the distribution of gases in planetary atmosphere.

 

[zachattack]

Oil and water don't mix because one is polar and the other nonpolar. Gases mix very readily, much faster than liquids. As UR quoted above there will still be some stratification, but the CO2 "blanket" effect is only temporary.

 

[marshallwms]

I may give this method a try since I hate siphon racking. To avoid O2 contamination, I normally spray CO2 into my kegs twice before I start, and once more at the end before I put the lid on and pressurize to carbonate. I figure all of this gets the O2 level down from the normal 20% to under 0.1%. I have never noticed any oxidation taste in my beers.

Putting a Gas-In connector on the keg, attached to nothing so the gas can go out freely, seems like it would work well vs. the need for a pressure regulator on the Gas-In side. Simplify.

 

[Ozzfan666]

and get a stainless racking cane

So I am trying to make things easier... I had this idea to pressurize a carboy with co2 (no more than 3-5lbs) with an orange carboy cap. Then hook my racking cane up as the dip tube through the cap to pick the beer up and then have a line to transfer the beer to my beer-out line on the corny keg. I'm trying to limit as much oxygen as possible. I have read some of the closed pressurized fermentation system methods so I think this idea should work. Anybody have any thoughts if this is a good idea or not? Thanks!

See photo

View attachment 136272

 

[rjbank]

Sounds like more work

 

[oakbarn]

If you were doing this at a company, you would win a huge lawsuit if the carboy busted. I personally would never hook up a pressure source to a glass bottle like this. The closed system with the clamp is an extremely bad idea. The glass carboy could explode. I am sure there is someone in this forum that has had one explode because of a blocked blow off tube during fermentation, and being able to put pressure (even 3 to 5 pounds) is too much for a glass. When you say “We do this without a problem”, I am reminded of a snake handler that died of a snake bite after 3 decades of handling snakes to show they were not as “bad” AS PEOPLE MADE THEM OUT TO BE. (Dieter Zorn). One mistake is all it took. If it only happen in one of a ten thousand times, I would not be the one who won the lottery. The transfer with gravity is a closed system from a carboy to a keg anyway as far as the carboy is concerned. I do agree that putting a blanket of CO2 in the receiving keg is a good idea. We do transfer from a 27 Gallon Stout Conical using low pressure to a keg with a totally closed system where the Beer is fed from the Conical to the keg via a Black Beer Out connector, the lid on the keg and the gray Gas In with a hose in Star San. We flush the keg with CO2 first. Even with everything steel, we are very careful doing this. We do not hook up the pressure from the CO2 to the Conical but use an Empty Keg that has 2 psi in it. We disconnect the CO2 from the “Pressure Keg” prior to hooking it up to the Conical. We let the pressure drain from the keg, disconnect, refill with 2 PSI and start again. Normally a couple of refills is all we need. We also let all the pressure out of the bottom of the keg after transferring. You can find out very quickly what 2 PSI is if you remove a fitting that has that small pressure on it. Working with Pressure has enough danger without the added glass bomb.
I would not recommend putting CO2 into a Glass Carboy, Period.

 

[mliptack]

I first purge the air out of a keg with CO2. Hook up a racking cane to the out-side of the keg.

Using a vacuum pump from Harbor Frieght I begin to drop the pressure of the keg. It takes only a few seconds of running to create the pressure necessary to start the siphon. Every minute or so I run the vacuum pump in a short burst just to encourage the speed of the siphon.

All hoses are standard beer line hoses. Nothing braided.

Also I do not replace the displaced volume in the carboy with CO2 but do cover the opening with sanitized aluminum foil.

I have been doing things this way for about 3 years now with no problems.

Don't have a $200 vacuum pump? Salvage the refrigeration unit out of an old refrigerator or freezer plug it in and find the side that pulls a vacuum - junkyard cost $20 at most.

Max

 

[mliptack]

I should have looked at all three pages before posting. And I would like to add to the topic of safety.

Do NOT use the method I mentioned above with glass. In my system, worst case scenario, my keg collapses (much like that children's science experiment where you boil a small amount of water in a soda can and dunk it upside down into water).

 

[Ozzfan666]

i use pressurre both in my glass carbouys, and glass growlers fitted with a shreader valve and hit it with 36 psi to quick carbonate some to take with, no problems

 

[AnOldUR]

 

[mliptack]

That is asking for a disaster to happen!

If I force carbonate I do so in a keg. Period. It's simply not worth it when glass is involved.

Put 36psi on a plastic carboy. See what happens. The flexing that occurs is happening to the glass too but much less noticeably. Next plastic stretches, glass for all intensive purposes, does not. So when the plastic fails it gives warning signs first. Glass isn't as friendly.

Think about what you're doing... 36psi doesn't sound like much, but the inside surface area of a 5gal carboy is somewhere in the realm of about 1500 in^2 at 36psi there is ~54,000 pounds of pressure being exerted overall on the glass...

I enjoy brewing, in fact so much I won't put my life at risk doing so.

 

[eluterio]

@ nextgenxx:

Im attempting to build this this weekend. I noticed you have a plastic pin or ball lock post on one end. This got me thinking to get a barbed fitting to fit my Gas post and use the ball gas lock. Now I have only one question.

Im using my dismantled corny keg ss dip tube as my racking cane. Im not sure what type of line to run from the cane to the ball lock out on my keg. Should I use the 5/16 beer line I have or use the 3/8th line I have?

What liquid line did you guys use??

 

[eltorrente]

I agree with others - don't seal that cap if you are going to use pressure. Don't use more than 1lb or 2lbs max.

When I transfer to a keg, I purge the keg first several times with CO2 to make sure O2 is out. I then make sure the racking cane tube is all the way to the bottom of the keg before transfer, and - like another poster said - I place a starsan-soaked rag over the opening of the keg, to minimize air circulation. I then gargle with listerene, just in case, and blow in the air side of the carboy cap to start the syphon. It works great.

I don't think that air flowing into the cap during transfer is an issue, since there is a blanket of CO2 - plus the beer isn't being splashed around during the transfer, so the O2 isn't going to enter into solution very easily. I could understand wanting to use a constant CO2 pressure into the carboy, though - just don't clamp it and use very minimal pressure.