# Vacuum in Carboy for long term storage ?



## vacuumpumpman (Oct 8, 2014)

I was wondering if you had some headspace and took a vacuum pump till you got down to approx 10-12 in hg and then made a good tight seal. 

I was thinking about adding argon to displace any possible oxygen in the beginning - any thoughts on this ??

This would be good for your normal 3 month racking and a gauge or similar will show that vacuum is still in the carboy


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## richmke (Oct 8, 2014)

Unless you have fully degassed the wine, the initial vacuum will not hold. Even then, I don't think the bungs are that air tight.


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## vacuumpumpman (Oct 8, 2014)

richmke said:


> Unless you have fully degassed the wine, the initial vacuum will not hold. Even then, I don't think the bungs are that air tight.



Rich - 
if the wine was not degassed enough - it would release CO2 - still protecting the wine.That is why I choose the vacuum pressure I did - at 10 in hg - it is not likely to pull off CO2 without some sort of agitation. I have tested my bungs and yes they will work - they are definitely holding a constant vacuum. 

Just wanted to know if this seemed like a practical idea ?


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## francois_du_nord (Oct 8, 2014)

Hell, I have no knowledge, only opinions on this. 

MicroOxegenation is a purported benefit of bulk in oak. If you vacuum seal with argon, you are eliminating oxygen so you wouldn't get the benefit of any oxygenation over time. 

Given what I've been reading in Iverson's "Home Winemaking", I'd think this method would be highly beneficial to whites (highly sensitive to oxygen uptake), less so for reds.


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## vacuumpumpman (Oct 8, 2014)

francois_du_nord
Thank you for your personal thoughts - this is designed more for those who have glass carboys rather than oak barrels. I agree aging in an oak barrel is always the best.


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## sour_grapes (Oct 9, 2014)

10 or 12 inHg means that you are only taking about 1/3 the air out. I.e., there is still 2/3 as much air in there as there was before. That wouldn't be good enough if the headspace was significant.

I believe I remember Mike (IBGlowin) saying that he has tested the residual gas after sparging with Ar, and found that there was still plenty of oxygen. Mike, I probably have some of that a bit garbled -- can you remind us?


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## WVMountaineerJack (Oct 9, 2014)

Any tiny flaw or variation would one night while you were asleep let the vacumm pressure go and suck in a bunch of air and you might not even know it happened. Not sure putting any pressure on a carboy for an extended time would be good for it either. WVMJ


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## vacuumpumpman (Oct 9, 2014)

Paul 
I questioned your theory – so I decided to test how much air displacement vs vacuum pressure-
I took the intake side to a 1 gallon empty container with a vacuum gauge inline - the exhaust of the vacuum pump into a full 1 gallon containing water with the neck submerged in water, and the gallon container bottoms up. The exhaust of the vacuum pump would have to force out the water to get a accurate reading. At 10 in hg of vacuum I displaced ½ gallon of water. At 15 in hg it was well over 75% of water displaced.


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## pjd (Oct 9, 2014)

vacuumpumpman said:


> Paul
> I questioned your theory – so I decided to test how much air displacement vs vacuum pressure-
> I took the intake side to a 1 gallon empty container with a vacuum gauge inline - the exhaust of the vacuum pump into a full 1 gallon containing water with the neck submerged in water, and the gallon container bottoms up. The exhaust of the vacuum pump would have to force out the water to get a accurate reading. At 10 psi of vacuum I displaced ½ gallon of water. At 15 psi it was well over 75% of water displaced.



Neat test Steve, I assume you mean inches mercury and not psi.


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## vacuumpumpman (Oct 9, 2014)

pjd said:


> Neat test Steve, I assume you mean inches mercury and not psi.



Yes - my bad - Thanks for the catch !


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## sour_grapes (Oct 9, 2014)

vacuumpumpman said:


> Paul
> I questioned your theory – so I decided to test how much air displacement vs vacuum pressure-



Steve,

It is not my theory. It is called "Boyle's Law," after the scientist Robert Boyle who first published it in 1662.

Your setup sounds like a good attempt to test Boyle's Law (which is not really in any doubt). Assuming the law is correct for the moment, your results could be consistent with an air leak in your plumbing; the leak would admit more air than was originally in the gallon container, and result in a larger volume of exhausted air than was taken from jug.

If you are still feeling experimental, you could try hooking up some more tubing and valves to allow you to refill your original gallon jug with the contents of the second one. I believe you will find that there is some air left over.


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## vacuumpumpman (Oct 9, 2014)

sour_grapes said:


> Steve,
> 
> It is not my theory. It is called "Boyle's Law," after the scientist Robert Boyle who first published it in 1662.
> 
> ...



I did look at Boyle's law and it mainly discussed pressure vs volume -
Not vacuum vs volume displacement - which I know that the exhaust is actually pressure not vacuum. It also had to fight the resistance of any liquid pressure per air flow 

I guess it all depends on your LPM on your pump - correct ?

The whole idea of this is - if you have a carboy that will not be able to top off - will this idea be suitable for this approach ? Within several bottles of topping off.

.


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## sour_grapes (Oct 9, 2014)

vacuumpumpman said:


> I did look at Boyle's law and it mainly discussed pressure vs volume -
> Not vacuum vs volume displacement - which I know that the exhaust is actually pressure not vacuum. It also had to fight the resistance of any liquid pressure per air flow



These are the same things, or rather, there is a one-to-one correspondence between "pressure" and "vacuum."

There is no such _thing_ as vacuum. It is not a thing. Rather, we use the term "vacuum" to mean the absence of pressure. Here on Earth, there is pressure from the air around us. If we lessen that pressure, like in a carboy, we call that "creating a vacuum," but it is really just a reduced pressure. There is still pressure in the carboy. We can use Boyle's law to figure out how much gas is still in the carboy. (When I say "how much gas," you can interpret this as "how much volume that gas would occupy at atmospheric pressure.")



> I guess it all depends on your LPM on your pump - correct ?



No, absolutely not. This is like saying that the distance from Chicago to Los Angeles depends on how fast your car goes.



> The whole idea of this is - if you have a carboy that will not be able to top off - will this idea be suitable for this approach ? Within several bottles of topping off.



People on this forum are of the opinion that a carboy must be topped off to within the neck of the carboy, leaving only, say, 100 ml of air in the carboy. Assuming that is true, then the vacuum approach is not suitable. Let's say you leave 2 bottles of air in the carboy (1500 ml), and let's say you pump it down to 15 inHg. You will have removed about 1/2 of the air molecules out of the carboy. But therefore you will have left 1/2 of them in, which would be the same as leaving 750 ml airspace (at atmospheric pressure) in an unpumped carboy. If you think that is okay, then you are fine.


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## vacuumpumpman (Oct 9, 2014)

Paul - 
I am not here to argue against you - I believe that LPM does factor in the equation.
You mention pump down to 15 in hg = well that should give you 375 not 750ml that you came up with according to my actual tests. If you use argon or shake the carboy a bit to cause CO2 will it not push out all the oxygen and or argon out of the carboy - correct ??

I only ask this question as I have alot of people who have excess carboy headspace and looking for an alternative rather than topping off with store bought wine.


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## sour_grapes (Oct 9, 2014)

vacuumpumpman said:


> Paul -
> I am not here to argue against you - I believe that LPM does factor in the equation.



I have absolutely no notion of what would inspire that belief. Perhaps you could try to articulate it?



> You mention pump down to 15 in hg = well that should give you 375 not 750ml that you came up with according to my actual tests.



Steve, I commend you for conducting the test. But please do not discard 350 years of empirical evidence by tens of thousands of other people based on what you did in your garage one time. If your experiment conflicts with 350 years of observation, the onus is upon you, not me, to seek resolution, to try to find any possible sources of error in your experiment.


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## richmke (Oct 10, 2014)

Never mind. Paul (below) is correct.


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## sour_grapes (Oct 10, 2014)

richmke said:


> I think you got it backwards. Atmospheric pressure at 750 ft above sea level (Chicago) is about 29 in of HG (32 ft of water).
> 
> Reducing to 10 in HG is a 2/3 reduction of air pressure, so 2/3 of the air would be removed.



Rich, Steve always uses gauge pressure, not absolute pressure. (As you know, gauge pressure = atmospheric pressure - absolute pressure.) You can see this in this particular case by looking at the order of the reported observations in the earlier post:



vacuumpumpman said:


> At 10 in hg of vacuum I displaced ½ gallon of water. At 15 in hg it was well over 75% of water displaced.


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## sour_grapes (Oct 10, 2014)

richmke said:


> As you suck out the air, proportional amounts of water vapor, alcohol vapor, O2, CO2, N2, etc are removed, thus reducing the vapor pressure of the water and alcohol. Water and Alcohol would then boil (evaporate) to restore the vapor pressure. Assuming 2/3 of the original vapor pressure was removed, this would require about another 1.7 inches worth of HG pressure to be removed, or about 10% more. 10% more of 66% is 73%, or about what you measured.



There is a problem with this applying this reasoning to the experiment Steve conducted. Steve measured the _volume_ of the exhausted gas, not its mass. The exhausted gas was held at atmospheric pressure. Any alcohol or water vapor that was vaporized at reduced pressure in the first carboy would have recondensed in the second carboy to maintain, as you point out, its equilibrium vapor pressure at room temperature. As a result, the exhausted volume of air would not have increased.


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## MrKevin (Oct 10, 2014)

Steve 
I have done what you are suggesting. I use the gas getter (sorry) but what I did was, while degassed my wine using the above product. He has a valve that can lock the vacuum. It works very well. I believe the locked vacuum was about 15hg and actually helped keep the bung tight.


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## vacuumpumpman (Oct 10, 2014)

Kevin
Have you stored your wine like this for any period of time?


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## MrKevin (Oct 10, 2014)

Steve 
I did store it for a few months. It was fully degassed and therefore did not loose its vacuum. I guess if the wine was not fully degassed, it would pull the gas from the wine the pressure would decrease. 

Kevin


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## vacuumpumpman (Oct 10, 2014)

MrKevin said:


> Steve
> I did store it for a few months. It was fully degassed and therefore did not loose its vacuum. I guess if the wine was not fully degassed, it would pull the gas from the wine the pressure would decrease.
> 
> Kevin



Kevin - I wanted to know - how was the taste of the wine ?
Do you feel it got oxygenated at all ? 
Do you feel that you lost any aroma ?
What type of wine was this ?

I fully understand about the decrease in vacuum if it has not been fully degassed - I thought about putting an automatic device to turn the pump on and off 

Thanks for any information - I plan to test with some white wine in a 1 gallon container - leaving it approx 3/5 full


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## MrKevin (Oct 11, 2014)

Steve 
The wine was a Malbec, I couldn't see/smell any change in color, aroma, or taste and no oxidation was noted. I though it worked very well. 
I did check it about every 2 weeks and verify that it stayed under vacuum (which it did). 
I will be curious to see how it works on a white. I have only done this one time only because I have been getting barrels for aging. 

Good luck on the experiment. 

Kevin


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## LoneStarLori (Oct 19, 2014)

Let me preface this by saying I know NOTHING about the science of this. However, if there were a product that allowed me to bulk age, even if it were just a few months, I would much rather have something that if I'm reading correctly, would be sure the wine is fully degassed and allow minimal air contact. Would it have a pressure gauge or something? I would prefer that to topping up. 
If it's fits and works with the AIO, even better. 


Sent from my iPad because I spilled wine on my MacBook. Waaaah!


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