Vacuum Degassers

[collitchboy]

I don't know how many people here vacuum degas but I was thinking of giving it a go on my latest apfelwein batch. I was able to get a 1g glass jug to withstand 25" Hg using a MightyVac and that gave me some confidence to scale it up some.

I have bought a vacuum ejector that can pull about 25" Hg using an air compressor and when it comes in I was going to try it on a recently purchased 5g glass carboy. Upon purchase of said carboy I noticed on the sides that it said not usable with pressurized liquids. At first I thought everything was great until it hit me that a vacuum is negative pressure and would probably fall under the blank statement 'pressurized liquids'.

For those with experience, do ALL glass carboys say this and people are still successful in vacuum degassing? Or are there really differences in glass carboys, sold for wine making, that would make one suitable for vacuum and another not?

 

[novalou]

I don't know how many people here vacuum degas but I was thinking of giving it a go on my latest apfelwein batch. I was able to get a 1g glass jug to withstand 25" Hg using a MightyVac and that gave me some confidence to scale it up some.

I have bought a vacuum ejector that can pull about 25" Hg using an air compressor and when it comes in I was going to try it on a recently purchased 5g glass carboy. Upon purchase of said carboy I noticed on the sides that it said not usable with pressurized liquids. At first I thought everything was great until it hit me that a vacuum is negative pressure and would probably fall under the blank statement 'pressurized liquids'.

For those with experience, do ALL glass carboys say this and people are still successful in vacuum degassing? Or are there really differences in glass carboys, sold for wine making, that would make one suitable for vacuum and another not?

Remember, with your gallon jug being smaller in diameter, it is better suited to handle pressure being positive or negative than a larger diameter carboy.

Your 5 gallon carboy can be successfully vacuum degassed provided it is completely full. Do not vacuum to 25" Hg, 10" or do should do it.

Glass is stronger in compression than tension. That's why glass carboy is tolerant of a slight vacuum and not forgivable at all in positive pressure.

 

[WVMJ]

Wear googles in case you get an implosion. What kind of carboy did you get? I have never seen that warning on the glass water bottle carboys (of course they never considered some nut would put a vacum on it). Mine have stood up to 25 with no issues but I make sure they are filled up to at least a few inches of the top. If you are really concerned put the carboy in a sink and put a towel over it in case it shatters, but most people just turn on the vacuum slowly. Another trick you can do is provide nucleation points, I do this by adding food grade boiling stones, it makes it easier to draw off the gasses.

Check out our degassing with boiling stones youtube

WVMJ

 

[collitchboy]

Remember, with your gallon jug being smaller in diameter, it is better suited to handle pressure being positive or negative than a larger diameter carboy.

Your 5 gallon carboy can be successfully vacuum degassed provided it is completely full. Do not vacuum to 25" Hg, 10" or do should do it.

Glass is stronger in compression than tension. That's why glass carboy is tolerant of a slight vacuum and not forgivable at all in positive pressure.

Only 10"? I thought you had to go much higher to efficiently get the gasses out. I have one vacuum ejector already that will pull about 14" Hg, would that be sufficient?

Wear googles in case you get an implosion. What kind of carboy did you get? I have never seen that warning on the glass water bottle carboys (of course they never considered some nut would put a vacum on it). Mine have stood up to 25 with no issues but I make sure they are filled up to at least a few inches of the top. If you are really concerned put the carboy in a sink and put a towel over it in case it shatters, but most people just turn on the vacuum slowly. Another trick you can do is provide nucleation points, I do this by adding food grade boiling stones, it makes it easier to draw off the gasses.

Most of what I have read suggests that filling to the shoulders is sufficient. You would fill up in to the neck of the carboy? Because it is a 5g carboy?

Thanks!

 

[WVMJ]

Up to the shoulders which is just a few inches from the top (which I mean the bottom of the neck), I should have taken a picture WVMJ

 

[DoctorCAD]

25" has not been a problem in any of my glass carboys.