Vacuum splash rack & oxidation

[tonyt]

I usually splash rack all my wine each time I rack thinking that it will help drive off any gas that might still be left in the wine. Then I was reading an article about keeping air (oxygen) away from wine in every step. So if I splash rack into a carboy under vacuum should I worry about oxidation?

 

[Rocky]

Tony, I splash rack at just about every opportunity and I do not worry about O2 because the exposure is for such a short period of time and then I fill the carboy to within an inch or two of the stopper. I think if one works fast there would be no problem.

 

[ibglowin]

If its a white wine I try hard to keep it to a minimum. It its a red wine these days I say bring on the oxidation (within reason of course).

 

[SBWs]

If you are under a vacuum there is little to no air in the carboy to cause oxidation. What you have in there is co2 being pulled from the wine.

 

[tonyt]

If you are under a vacuum there is little to no air in the carboy to cause oxidation. What you have in there is co2 being pulled from the wine.

That's kind of what I was thinking but wanted y'all to weigh in.

 

[vacuumpumpman]

If you are under a vacuum there is little to no air in the carboy to cause oxidation. What you have in there is co2 being pulled from the wine.

That is a very good explanation of it - I will typically always splash rack under vacuum. I takes about 4 minutes to transfer 6 gallons of wine.

 

[JohnT]

Ask yourself this.... If you splash rack every time, and you have made several batches of wine, how many of those batches have oxidized?

The risk of oxidation is mostly dependent on the PH level and the amount of tannins in your wine. As long as these two level are where they should be, you should have a very low risk of oxidation when splash racking.

Even though there is minimal risk, I splash rack when needed (when I have hydrogensulfide issues) and do just a standard racking otherwise.

johnT.

 

[Lurker]

If you mean to allow the wine to fall into the carboy while vacuum racking, I've been doing it for a few years with no ill effects. I do give it a final shake before bottling to get out the last bit of gas but that is one of the benefits of vacuum racking.

 

[fafrd]

If you are under a vacuum there is little to no air in the carboy to cause oxidation. What you have in there is co2 being pulled from the wine.

If this is correct, it should be true when bottling under vacuum as well, no?

I see that most/all of the commercial vacuum bottling systems divert the incoming wine to the sides of the bottle rather than letting it splash straight to the bottom.

If this is merely to reduce the amount of foaming, I get it, but most of them clain that it avoids oxidation and is 'gentler' on the wine.

Is there any benefit to filling down the side of the bottle under vacuum rather than splashing straight down or is it just done to minimize foaming!

 

[vacuumpumpman]

The allinonewinepump was designed to be under vacuum and go down the side of the bottle to prevent any foam from agitation of the wine, or any left over CO2.
I now have a precision vacuum release valve which aids in this process by adjusting the vacuum even lower while bottling and keeping better flow control.

 

[Johnd]

If your wine is still releasing CO2 as you are bottling, unless you intend carbonated wine, your wine is not ready to bottle.

 

[fafrd]

The allinonewinepump was designed to be under vacuum and go down the side of the bottle to prevent any foam from agitation of the wine, or any left over CO2.
I now have a precision vacuum release valve which aids in this process by adjusting the vacuum even lower while bottling and keeping better flow control.

I agree with the comment that if your wine is still releasing CO2, it is probably not ready to be bottled, but even if you want the potential of further CO2 release under vacuum during bottling, that would be an argument in favor of 'splash bottling' (a stream straight to the bottom) rather than 'going down the side'.

So why is splash bottling harmful to the wine? Is it the increased 'agitation' that is harmful? Is it increased oxidation (under vacuum)? Is it increased foaming?

If it is primarily increased foaming that is the concern, is the formation of foam itself harmful to the wine or that increased foam can result in inconsistent fill height?

 

[DoctorCAD]

Thin film degassing...that's the reason for running down the side. The wine spreads out and gives a huge increase in surface area for the vacuum to "work" on.

 

[fafrd]

Thin film degassing...that's the reason for running down the side. The wine spreads out and gives a huge increase in surface area for the vacuum to "work" on.

I hear 'ya, but that means the reason to bottle 'down the side' is to promote further degassing, and if the wine is already sufficiently degassed prior to bottling, there is no advantage to 'down-the-side' bottling under vacuum over splash-bottling.

If your wine is already sufficiently degassed, and if you are bottling under vacuum where oxidation should be less of a concern, I'm trying to nail down whether there is any subatantive disadvantage/drawback to splash-bottling over 'down-the-side' bottling.

 

[Mismost]

I hear 'ya, but that means the reason to bottle 'down the side' is to promote further degassing, and if the wine is already sufficiently degassed prior to bottling, there is no advantage to 'down-the-side' bottling under vacuum over splash-bottling.

If your wine is already sufficiently degassed, and if you are bottling under vacuum where oxidation should be less of a concern, I'm trying to nail down whether there is any subatantive disadvantage/drawback to splash-bottling over 'down-the-side' bottling.

yes there is....down the side produces much less foaming when bottling, which in my mind, is reason enough.

 

[Johny99]

Remember that a vacuum is simply lower than ambient pressure. Depending on your pump, there is air and thus oxygen in the bottle or carboy. So while there would be less air and thus oxygen entrainment under vacuum, it isn't zero. So splash racking into a vacuum will entrain more air than a laminar flow down the side. It is the presence of gas pressure under the film of wine that creates foam.

 

[fafrd]

yes there is....down the side produces much less foaming when bottling, which in my mind, is reason enough.

Foaming is bad if it results in inconsistent fill height, but does it cause any issues other than that?

 

[fafrd]

Remember that a vacuum is simply lower than ambient pressure. Depending on your pump, there is air and thus oxygen in the bottle or carboy. So while there would be less air and thus oxygen entrainment under vacuum, it isn't zero. So splash racking into a vacuum will entrain more air than a laminar flow down the side. It is the presence of gas pressure under the film of wine that creates foam.

I agree, most home vacuum systems seem to reduce pressure to somewhere between 1/2 to 1/3 of ambient, and this ought to mean that the amount of oxidation you get when splashing in such a partial vacuum is ~1/3 - 1/2 of what you'd get splash-racking/bottling under siphon, right?

So is that the reason a laminar flow down the side is preferable, under partial vacuum or not? Is oxidation during bottling the issue you are trying to avoid?

 

[Johny99]

It is the one I try to avoid. I've never really grasped the "bruise" the wine issue, or at least ever had it explained to me.

 

[vacuumpumpman]

I agree with alot of the statements above -

Take any bottle of wine that is corked - commercial or homemade and shake it up . You will see foam inside the bottle - That is exactly what is happening as you fill your bottle. I like to keep all my liquid levels very consistent.

There are alot of people who bottle their wine too early and will get some CO2 out when bottling - but mainly I believe it is just agitation of the wine - so going down the side helps prevent this.