Cube air vanishing?!

[DJ_L3ThAL]

Have had a Rogers clone in a no chill cube in storage from a month or so ago. It had about 100mL of air when I cubed and it had cooled to room (garage) temps. But since has slowly reduced in size, the air bubble that is. It is almost completely gone and no air at all in the cube... seems reverse logic as to what I would expect if it was infected where it would expand and the air bubble size would INCREASE as pressure builds.

Having said that the kink in the wall where I pushed the cube in slighly to squeeze as much air out as possible seems to also be less than I remember, but I may be dreaming that one.

Anything to be concerned about? Am thinking of just cracking the lid for a sniff and better visual. But wondering if anyone has a reasonable explanation for me to RDWHAHB such as thermal expansion/contraction would somehow affect this. But it has been getting hotter if anything lately so I'd expect it to all expand as opposed to contract.

 

[Danscraftbeer]

I've only cubed twice and that air space disappeared overnight basically when it was slow cooling. Its absorbed I guess is the best term into the liquid. After a month though is different. Or the same, :unsure: . I've only kept in cube for a week at the most. If its not bloated then its all good I'd think.
Don't open it! until pitching.
No head space! Its probably as good as cubing technique could get.

 

[TSMill]

Just obeying Henry's law, as gasses are prone to do.

 

[Danscraftbeer]

Who's Henry? sorry. I think its fair to say that a bubble that grows in size is a bad sign. If its disappeared then that's good. Just don't open it!.

 

[DJ_L3ThAL]

Increase in temperature for water and Air (Nitrogen) means more of that Air can be dissolved into solution, so perhaps I am just seeing the gas being dissolved into solution because it's now warmer in Melbourne then it was about 4 weeks ago when we had a couple weeks of moderate weather. I wanted to try and pitch this cube this weekend anyway, but am now leaning towards putting it in the fridge for a few hours to see if as it cools down, the bubble returns. Yeah science.

 

[Camo6]

Sounds more like Roger's law to me.

Don't forget, you've removed most of the oxygen by boiling so I imagine the re-absortion would be pretty rapid. Although I have no knowledge on the subject and am pretty much talking out my ***.

 

[twizt1d]

botulism ate it

 

[Danscraftbeer]

:lol: Stop friggin round dudes this is serious.

Increase in temperature for water and Air (Nitrogen) means more of that Air can be dissolved into solution, so perhaps I am just seeing the gas being dissolved into solution because it's now warmer in Melbourne then it was about 4 weeks ago when we had a couple weeks of moderate weather. I wanted to try and pitch this cube this weekend anyway, but am now leaning towards putting it in the fridge for a few hours to see if as it cools down, the bubble returns. Yeah science.

I would only cool it to pitch temp of the yeast you choose. and- Relax don't worry and have a home brew. (I had to look that up!)
:chug:

 

[wide eyed and legless]

Is, or was the cube sealed satisfactorily , if you have lost the vacuum then wouldn't the liquid take up that space in the warmer weather?

 

[DJ_L3ThAL]

Is, or was the cube sealed satisfactorily , if you have lost the vacuum then wouldn't the liquid take up that space in the warmer weather?

Yeah mate, they are DG cubes, lids and seals are insane, barstard to open them too!

For ***** and giggles, I've put said cube into fridge for an hour or so to drop the temp a few degrees so will report back if the gas space returns.

 

[JDW81]

Anything to be concerned about? Am thinking of just cracking the lid for a sniff and better visual. But wondering if anyone has a reasonable explanation for me to RDWHAHB such as thermal expansion/contraction would somehow affect this. But it has been getting hotter if anything lately so I'd expect it to all expand as opposed to contract.

Bring it round to my place and I'll ferment and drink it for you to see if it's OK.

If something was growing in there then it would be blowing up like a Collingwood supporter at an umpire.

RDWHAHB

JD

 

[Danscraftbeer]

I forgot to buy my tattas tickets this week. Instead I will put down $50 at 1:1 that the Gas bubble does not return no matter how much you chill.

 

[TSMill]

Over time the gas will absorb into the liquid until equilibrium is achieved. The sealed cube is analogous to a force carbed keg which naturally comes down to serving pressure as the gas is absorbed.

Also, cooling would make any bubble smaller, not bigger because cold liquid will hold more gas than hot, and also PV=nRT

 

[DJ_L3ThAL]

So the bubble didn't come back, lol.

Wondering now that it is chilled to fridge temp if there is any down side to taking it out and letting warm back up to ambient? I can leave it at fridge temps until I open it but curious how much temp fluctuations can risk other bugs etc from kicking off... Particularly as my recent cube infection appears to have been kicked off by higher ambient temps

 

[n87]

Boiling drives off alot of the gasses in the liquid (wort).

Gasses are also more soluble in colder liquid (until about 2C, at which it gets less soluble again, hence bubbles in ice)

so as the Wort cools, it absorbs (pasteurised) air that is left in the cube
If the air bubble is small enough, it will be fully consumed.

Table showing solubility of air in water against some old and outdated temperature scale:
http://www.engineeringtoolbox.com/air-solubility-water-d_639.html


If the air bubble returns however.... you have a different problem



As an aside, this is also why CO2 is more readily absorbed at a lower pressure in the fridge

 

[DJ_L3ThAL]

Understand that but there's no time dependence in the formulae. So how could it take a month, seems quite slow particularly as temperature was warming up if anything. Anyway I'm confident this cube is ok now guess i have just never noticed the reduction in bubble size in cubes as I was only looking for increases in size.... thanks for the info!

 

[n87]

Didnt see your time frame...
My bubble usually disappears over night.

In that case, it might have jumped into the lid?

 

[Adr_0]

20L of wort will decrease to about 96% of that volume in going from 95°C to 25°C due to density increasing and mass staying the same.

200mL of air will decrease to about 81% of that volume in going through this same temperature change, i.e. will reduce in volume more.

Although some of Henry's law may be at play, I would say that condensing of moisture from that air would be more of a factor, which will further exacerbate the above.

The above numbers will change a bit given the volume and pressure of the cube changes, but relatively speaking the air will reduce in volume by a lot more than the wort will for a given temperature change.

 

[Adr_0]

Over that period of time you will probably get some absorption. I would have thought temperature changes would have had more of a noticeable impact on volume (over a 24hr period) but over the course of a month this might be noticeable.

Low temperature and high pressure = more absorption. Low pressure does not equal more absorption.