suckback

[Ozarks Mountain Brewery]

 

[Vodka Drunkenski]

How much suck back (volume) would you get in a 23 L carboy that was filled
completely, no headspace? Also, once the temperature has cooled to the
environment, will there be further suck back occurring, for instance, if the carboy
were topped up, and sealed after the temp drop? Trying to wrap my head around
the physics involved...there seems to be 2 effects at play, the contracting liquid,
and the contracting gasses.

 

[Minbari]

How much suck back (volume) would you get in a 23 L carboy that was filled
completely, no headspace? Also, once the temperature has cooled to the
environment, will there be further suck back occurring, for instance, if the carboy
were topped up, and sealed after the temp drop? Trying to wrap my head around
the physics involved...there seems to be 2 effects at play, the contracting liquid,
and the contracting gasses.

if you filled it with zero headspace or sealed it, you will have bigger problems, lol.

I use a 3 peice airlock, when I cold crashed, I have had it suck that airlock dry before. why I started using a balloon to compensate

 

[Vodka Drunkenski]

if you filled it with zero headspace or sealed it, you will have bigger problems, lol.

I'm speaking strictly after the temperature of the carboy has dropped to the
ambient temp, and the initial suck back has occurred. Will there be further
suck back if topped up and sealed......and more importantly why? Thanks.

 

[Vodka Drunkenski]

I started using a balloon to compensate

That's another thing.....if a carboy can withstand the positive pressure enough to inflate
a balloon, then couldn't a balloon be stretched over the neck to "reverse inflate" to
accommodate the oxygen that gets sucked in. Wouldn't the balloon provide a barrier to
the oxygen? Is there a reason why it wouldn't inflate inside, to take up the space? I'm sure
the balloon would fail before the carboy would.

 

[Ward Chillington]

.there seems to be 2 effects at play, the contracting liquid,
and the contracting gasses.

More like 3 things....but I'm not sure if that's your question? What are you actually trying to figure out?

Sure, less headspace, less suck back from the less volume of air molecules but then there's the greater volume of liquid molecules so the only other factor is the delta in the starting temp to the crashed temperature. Bigger delta, smaller molecules more suck. Use the balloon or a clean food grade bag that @Minbari sez!

 

[Minbari]

I'm speaking strictly after the temperature of the carboy has dropped to the
ambient temp, and the initial suck back has occurred. Will there be further
suck back if topped up and sealed......and more importantly why? Thanks.

are you just peaking therory? cause I dont know what you would have topped it up with? once it cools and you add yeast it cant be at the top. you will have such a mess once fermentation starts

 

[Minbari]

That's another thing.....if a carboy can withstand the positive pressure enough to inflate
a balloon, then couldn't a balloon be stretched over the neck to "reverse inflate" to
accommodate the oxygen that gets sucked in. Wouldn't the balloon provide a barrier to
the oxygen? Is there a reason why it wouldn't inflate inside, to take up the space? I'm sure
the balloon would fail before the carboy would.

I am sure you could........I use mylar baloons, so there is no pressure. once it is fully inflated the extra goes out the airlock as normal

 

[Vodka Drunkenski]

are you just peaking therory? cause I dont know what you would have topped it up with? once it cools and you add yeast it cant be at the top. you will have such a mess once fermentation starts

Yes....theory, but I'm afraid you're misunderstanding me. I'm talking about "cold crashing" an already fermented beer.

If I have a 23L carboy completely fully topped up with fermented beer...
I take that carboy into a cold environment...
The carboy experiences "X" amount of suck back (contraction)...
I'm not concerned with oxygenation for this example...
I then fully top up the carboy again with the same beer at same temp...
The carboy gets sealed...
No further temperature change occurs...
Does the beer inside the carboy continue to "suck back" for any reason?
Does Vodka's carboy implode, causing him to swear a blue streak? lol

This is what I was getting at.

 

[Vodka Drunkenski]

I am sure you could........I use mylar baloons, so there is no pressure. once it is fully inflated the extra goes out the airlock as normal

Yes....not arguing that the CO2 filled balloon is the better way, just exploring the theory behind this
kind of stuff.

 

[Minbari]

Yes....theory, but I'm afraid you're misunderstanding me. I'm talking about "cold crashing" an already fermented beer.

If I have a 23L carboy completely fully topped up with fermented beer...
I take that carboy into a cold environment...
The carboy experiences "X" amount of suck back (contraction)...
I'm not concerned with oxygenation for this example...
I then fully top up the carboy again with the same beer at same temp...
The carboy gets sealed...
No further temperature change occurs...
Does the beer inside the carboy continue to "suck back" for any reason?
Does Vodka's carboy implode, causing him to swear a blue streak? lol

This is what I was getting at.

assuming no temp change, then no. it wont.

yes, lots of cursing if it does, lol

 

[west1m]

With a full carboy you will get very little suckback. I am sure there is some liquid shrinkage. With a Sidel with almost three gallons of head space I had to go to two gallon zip lock bags as one gallon wasn't quite enough co2.

 

[Vodka Drunkenski]

assuming no temp change, then no. it wont.

With a full carboy you will get very little suckback.

Thanks guys.