Cellar Craft Vacuum Degassing

[Sudz]

1. I vacuum degass all my kit wines. Has anyone ever experienced a problem from this practice?

 

[vacuumpumpman]

As far vacuum degassing there are only benefits from this - unless you apply straight vacuum to the vessel and you are actually boiling the alcohol.

That is one reason why I like the approach of vacuum racking - it removes the CO2 as it is being transferred between carboys.

If you want more detailed info - please PM me with a phone # and I will call you back at my earliest convenience

 

[SouthernChemist]

I transfer my wines under reduced pressure/partial vacuum all the time (thanks to Steve's wonderful All-in-One setup) without any issues. This does help remove the CO2 in the wine. I could see a problem if you put the wine under a straight vacuum for an extended time period. In that case, you run the risk of stripping not only ethanol/water (they will come over together) but also other compounds in the wine.

 

[MrKevin]

I vacuum degass all my wines. I have a pump that applies direct vacuum with no problems. I disagree that low vacuums boils alcohol (24hg's). I know it is possible to boil the alcohol from wine, but not at the levels your normal degasser produces, Winemaker mag has some good articles on it.

 

[cimbaliw]

I do almost all kits each one is vacuum degassed without any issues. I usually vacuum rack each batch about 4 times. Generally on the third racking I add the sulphite/sorbate mix. Before the final racking I add the clearing agents. I've started adding tannin riche if I feel it's appropriate. Often times I'll use the racking cane to stir during transfer or lift the carboy and give it a good sloshing during early fill.

BC

 

[vacuumpumpman]

I will mostly agree with MrKevin
You mention this -(but not at the levels your normal degasser produces) there are so many different type of vacuum pumps out there.

The other bigger factor is temperature and altitude has alot of factors in boiling alcohol from wine.

I know for a fact that a wine at approx 72 degrees at approx 700 feet above sea level will typically start to boil off at 28 in hg -

I believe the safest method - is to vacuum degas while transferring

 

[Sudz]

Thanks guys,

I never exceed about 24"hg so it would appear nothing negative is occurring. Good to hear the same perspective from others.

 

[sour_grapes]

The other bigger factor is temperature and altitude has alot of factors in boiling alcohol from wine.

I know for a fact that a wine at approx 72 degrees at approx 700 feet above sea level will typically start to boil off at 28 in hg -

I would like to note that the the altitude (i.e., ambient pressure outside the vessel) has no effect on what goes on inside the vessel, i.e., it does not change the absolute pressure at which a liquid will boil. It does change how some pressure gauges read, however. This is one reason why I much prefer a gauge that directly reads the pressure inside the vessel, rather than ones (like the one that Steve refers to) that measure the difference in pressure between inside and outside. But absolute pressure gauges are, of course, more expensive.

You can read more about the distinction here, if you are so inclined: http://en.wikipedia.org/wiki/Pressure_measurement .

 

[vacuumpumpman]

Paul
I know that alcohol will boil at a much lower temperature at higher altitudes -
with that being said - would it not boil under vacuum at a lower vacuum also ?

I do not have a scientific background like some of you do -

I did find this that I was going off of -
It sates it will boil at 29.2 in hg at sea level and it will boil at 20.58 at 10,000 feet above sea level and even less as the altitude increases

 

[SouthernChemist]

The boiling point is the point at which the vapor pressure of liquid is equal to the pressure around the liquid. If you lower the pressure of the environment, you will lower the temperature at which a liquid boils because the vapor pressure does not have to be as high. In the case we're all talking about, it's the actual pressure inside of the container of wine that matters...not the pressure difference or the air pressure outside of the container.

 

[sour_grapes]

Southern Chemist is correct, of course. I suppose what I should have stressed more than I did, Steve, is that when you read, say "28 inHg" on your gauge, that is the DIFFERENCE between the pressure inside your carboy and the pressure outside your carboy. But the wine doesn't care about this difference. It only cares about the pressure inside your carboy, and how that compares to the vapor pressure of alcohol at that temperature. I hope I was clearer this time, but feel free to ask me to clarify if not.

There are gauges available that read the ABSOLUTE PRESSURE inside the carboy, without measuring with respect to the atmosphere. But they are more costly.

 

[Putterrr]

If you have the gauge that reads inside the carboy, have you ever had readings from both at the same time. Just curious to see what the difference would be.

thx

I would like to note that the the altitude (i.e., ambient pressure outside the vessel) has no effect on what goes on inside the vessel, i.e., it does not change the absolute pressure at which a liquid will boil. It does change how some pressure gauges read, however. This is one reason why I much prefer a gauge that directly reads the pressure inside the vessel, rather than ones (like the one that Tom refers to) that measure the difference in pressure between inside and outside. But absolute pressure gauges are, of course, more expensive.

You can read more about the distinction here, if you are so inclined: http://en.wikipedia.org/wiki/Pressure_measurement .

 

[sour_grapes]

I do not have such a gauge on my winemaking equipment. (I use them routinely at work.) But it is not rocket surgery -- the sum of the two readings would add up to whatever the atmospheric pressure happened to be that day.

 

[DoctorCAD]

I do not have such a gauge on my winemaking equipment. (I use them routinely at work.) But it is not rocket surgery -- the sum of the two readings would add up to whatever the atmospheric pressure happened to be that day.

Thats just what I was going to say...it really doesn't matter because they would add up to the same thing.

It really doesn't matter, as long as you use the same measurement system before and after.

 

[sour_grapes]

It really doesn't matter, as long as you use the same measurement system before and after.

Before and after what?