Extreme Evaporation?

[crushday]

I pressed Cab Franc must on Monday. One of the vessels I racked to is a six gallon PET carboy with a breathable stopper.

If you look at the wine level in the carboy it’s much lower than the stopper. However, two days ago it was almost touching. As I moved the carboy to where it is now I sloshed some which is why you can see wine remnants on the stopper. You can also see evidence of fermentation as primary buttons up and secondary takes over.

Question - where did the wine go? Temp hasn’t changed and there’s no evidence of a leak. Did it evaporate?

 

[stickman]

Initial volume might be greater due to submerged co2 bubbles being attached to lees and pulp, once the co2 is released the head space comes back.

 

[crushday]

Another thing I thought of is the wine was likely warmer when I put it in that carboy than it is now considering it was open fermenting with a loose cap. With it a little cooler now the must volume has lowered.

Seems like I asked a question too quickly...

 

[stickman]

Temperature will have some effect, though I was basing my comment on your initial post indicating there was no temperature difference. I do see a fairly large level change with my 54l demijohns, after taking them out of the cellar at 58F and allowing them to come up to room temp 70F.

 

[KCCam]

Temperature will have some effect, though I was basing my comment on your initial post indicating there was no temperature difference. I do see a fairly large level change with my 54l demijohns, after taking them out of the cellar at 58F and allowing them to come up to room temp 70F.

Temperature changes the volume of 6 gallons by about 1 ounce for every 10°F. In the neck of my carboys (1 1/4” ID), that correspond to 1 1/2”. Dissolved CO2 would change the density of a liquid too, but I have no idea how significantly. Maybe a combination of both.

 

[crushday]

Temperature will have some effect, though I was basing my comment on your initial post indicating there was no temperature difference.

Stickman, we’re falling prey to my poor communication skills and hasty typing...

What I should have said in the first post is the room temperature was the same. A few minutes later I realized the must temp had to be different and undoubtedly the culprit in this investigation.

So sorry for the waste of time for anyone looking at this.

 

[Boatboy24]

Barometric pressure can play a part as well.

 

[sour_grapes]

Barometric pressure can play a part as well.

I don't believe this is the case. Water is essentially incompressible. If you double atmospheric pressure on the wine in your 23 L carboy, you would shrink the volume by about 1 mL (i.e., by 0.005%). This will not be observable.

A change in pressure can visibly alter where the water level in an airlock is by changing the volume of the gas in the headspace.

 

[Ajmassa]

I don't believe this is the case. Water is essentially incompressible. If you double atmospheric pressure on the wine in your 23 L carboy, you would shrink the volume by about 1 mL (i.e., by 0.005%). This will not be observable.

A change in pressure can visibly alter where the water level in an airlock is by changing the volume of the gas in the headspace.

Hmm. So if atmospheric pressure changes are not causing the level in the carboy to change much (always thought it did) then what is causing random shifts in wine levels in the carboy?
I’ll notice this randomly at times while temp hasn’t shifted much. Figured there was a shift in atmospheric pressure. Not to a random carboy- but a random shift down or up in ALL the vessels.

 

[sour_grapes]

Temperature can do that...

 

[Ajmassa]

Temperature can do that...

I noticed it without any dramatic change in temps—or so I thought. (tapped into ductwork for AC in the basement. Maintains steadyish temps). One time I looked up if barometric pressure had shifted locally and it had- got my confirmation, and then just chalked it up pressure changes ever since.

Can only deduce the cinderblock wall my wines are stored against needs to be insulated

 

[KCCam]

Temperature can do that...

I’m not sure how much change you’re talking about, but for 6 gallons, 1°F will raise (or lower) the level in the neck of a carboy by more than 1/8” (assuming 1 1/4” inside diameter). No thermostat is going to control room temperature closer than 2 or 3 degrees. I agree with @sour_grapes, it won’t be due to pressure.