Degassing

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Time to show my age, degassing its like the commercial from the 1970's with Orson Welles talking about Paul Masson wine. WE WILL SERVE NO WINE BEFORE ITS TIME. To make good wine you can't be in a hurry. I have NEVER used a drill or a vaccum on my wine, my truck Yes, but wine No. Wine will degass on its own thru racking and aging. To tell if its done degassing, pour yourself a glass and drink it, if it taste fizzy( a young wine) at all, it needs more time to age. You CANNOT ferment, rack and bottle in a month or 2, and have anything that resembles a quality wine, my 2 cents. Have a wonderful day:db
 
Carbon dioxide in wine

CO2 is needed at some level in both red and white wines, even more so in champagne or sparkling wines. Too much are it and you get a fuzzy taste or a prickly feeling on your tongue and your wine taste buds can pick up the carbonic acid in the wine itself. Sommeliers are supposed to be able to detect 700 to 800 ppm in wine, while most of us have a detectable limit of 1000 ppm. Fully saturated wine, or even supersaturated wine, like the stuff that has yet to stop bubbling (after primary fermentation) comes in at about 1500 to 2000 ppm, depending on temperature.
The rate of degassing relates to the partial pressure of CO2 in the atmosphere directly above the liquid and the concentration of CO2 in the wine. (a consequence of Henry's Law). The amount of gas removed is also related to the surface area of the fluid that is is exposed to the partial pressure. So if you just have a small area, like the neck of a carboy, available for gas exchange, then it will take a long time!!!
And if you have negligible difference between the partial pressure of CO2 and concentration, it will take a long time for the CO2 to leave the fluid.
Why does the wine whip and splash racking work so well? Well, it exposes a large surface area to a very low partial pressure of atmospheric carbon dioxide with a very short transport distance ( the thickness of the wine curtain as it falls down the side of the carboy). What a wine whip does to the rest of he constituents of the wine is unknown to me, but it can't be good.
Tim V has suggested that a vacuum assisted degassing system is probably OK, however the temperature has to fairly high like 74 deg F so the CO2 can escape easier ( less soluble at higher temp). Unfortunately, higher temps also impact the other wine constituents, including the esters that make up the nose and initial taste of wine. Hence we get a wine kit taste and no nose. Wine cellars that allow "time" to degass wine are kept at much lower temps than 74 deg. So a solution may be to degas wine at higher vacuum levels, at lower temperatures. That is what I do.
My vacuum levels are about -.8 of an atmosphere, and temp is 62 deg F. I also control the flow rate in the transfer racking to give the pressure differential sufficient residence time to be effective. That is a bit of guess right now, but someplace about 4-5 min for 23 liters.
And to make it even more interesting, I use plastic carboys. But that's another story.
That is my 2 cents (Cdn), or 1.5 cents (US).
Ric,WTFfF ( Wine Time Factory for Friends)
 
As someone that suffered through fizzy wines in my first couple of years making wine, let me tell (nay iNSTRUCT, nay ORDER) you to purchase an Allinone vacuum pump. Just cut to the chase scene in the movie and get this pump. It will be the best money you will have spent so far in wine making.

My wines improved remarkedly with no fizzy wine complaints from my wife. Shame on you for 6 weeks if you don't get one.....
 
Why does the wine whip and splash racking work so well? Well, it exposes a large surface area to a very low partial pressure of atmospheric carbon dioxide with a very short transport distance ( the thickness of the wine curtain as it falls down the side of the carboy). What a wine whip does to the rest of he constituents of the wine is unknown to me, but it can't be good.

I think what the wine whip does is cause a low-pressure region in the "wake" of the whip. (Think cavitation, as happens at the tips of a boat's propeller.) The reduced pressure allows a CO2 bubble to nucleate; once the bubble reaches a certain size, the CO2 will not be redissolved into the liquid, but will instead bubble up to the surface. (This is like the stream of bubbles coming up from the bottom of a champagne glass; in that case, small voids on the bottom of the glass act as nucleation sites for the supersaturated CO2.)
 

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