Pambianchi study on degassing

[derunner]

Here is an easy experiment.

Open a can of pop, drink half, set it on the counter and leave it over night. Check it the next morning as taste for carbonation (CO2).

Repeat the experiment only this time place the can of pop in the fridge overnight.

Guess which can still has CO2?

I've done this many times. A flat coke would be my morning caffiene before running a marathon. Coffee was too hard on my stomach on race day jitters. A flat coke worked great. I found at room temperature, much of the co2 is still in the coke can after sitting overnight. I would have to "splash rack" it back and forth between 2 large cups to get the co2 out.

 

[ibglowin]

Perhaps you should have degassed it with a vacuum pump......

 

[BobF]

... with a sanitized bottle brush shoved inside ...

 

[ShepherdQ]

There's absolutely no doubt in my mind that using the vacuum pump is far superior to stirring, even drill stirring.

So why do you say this? I'm trying to wrap my head around Pambianchi's results and see why anyone would use a vacuum pump. It doesn't get CO2 out nearly as quickly, and you have to use it for 45 mins at least to be O2 neutral. Vacuum racking surely doesn't take that long, though?

 

[ibglowin]

ShepardQ,

Did you miss the whole "experiment was conducted at 55 degrees F" thing?

CO2 does not come out of solution very easily at those temps.

He basically "beat" the CO2 out of the wine with a drill.

The vacuum pump is much gentler on the wine and doesn't whip O2 into the wine during the process.

If it didn't work do you think so many of us would be using vacuum pumps to degas our kit wines?

 

[BobF]

Lower temps also make it easier to take up O2

 

[MonkeyK]

But where is the O2 that is being introduced into the wine coming from? As vacuum decreases the amount of gas above the surface of the wine, 02 is also decreased. So that the amount increases suggest either a flaw in the process or measurement, or that the method somehow makes 02 absorption more effective. Does the vacuum, make the wine surface more receptive to 02? Does simply reducing C02 and S02 do that? Or is it possible that the regular stopping the vacuum and taking a sample greatly affected the effectiveness of vacuum degassing --and possibly even introduced 02 into the wine and samples?

 

[robie]

ShepardQ,

Did you miss the whole "experiment was conducted at 55 degrees F" thing?

CO2 does not come out of solution very easily at those temps.

He basically "beat" the CO2 out of the wine with a drill.

The vacuum pump is much gentler on the wine and doesn't whip O2 into the wine during the process.

If it didn't work do you think so many of us would be using vacuum pumps to degas our kit wines?

I agree. Would have been interesting had he repeated the experiment at 74F; I think the vacuum pump would have performed much better (even without the bottle brush!!!).

 

[Dugger]

So why do you say this? I'm trying to wrap my head around Pambianchi's results and see why anyone would use a vacuum pump. It doesn't get CO2 out nearly as quickly, and you have to use it for 45 mins at least to be O2 neutral. Vacuum racking surely doesn't take that long, though?

Sorry, I've been off the computer all day so just seeing this now.
I say this from my own personal experience - I used to stir, manually and with the drill stirrers, and still ended up with gas in the wine. I got a vacuum pump from Wade almost 2 years ago now and my wine since then has been degassed like never before.
Vacuum racking takes no longer than siphon racking, so doesn't take long at all and doesn't add any more time to the process.

 

[deboard]

I'm 4 kits in, and I use a drill attachment to degas, basically just an oddly shaped plastic rod designed for degassing. I just degassed my CC Red Mountain Trio, which has oak cubes for use after secondary.

I ended up dropping the cubes in as I was racking without thinking of degassing, so I degassed with the cubes in. I was surprised that it seemed to be much more effective! The foam just about came out of the top of the carboy every time. The cubes would spin with the wine and get dispersed, and then when I stopped or changed directions they would bring up all kinds of bubbles with them.

Anyone else seen this?

 

[BobF]

Yep. I add a few oak chips when degassing a stubborn batch. Sometimes it works well!

 

[MonkeyK]

I didn't make that connection, but thinking back I can say that of the 4 kits I have done, the only one with gas problems was the one where I did not have oak cube in the secondary. (Then again, I only just now discovered swirling while vacuum degassing)

 

[ShepherdQ]

I ended up dropping the cubes in as I was racking without thinking of degassing, so I degassed with the cubes in.

Cool, I might try this with the Cab Sav I'm currently doing. I can now say the cubes act as a nucleation device! You learn wonderful things making wine...

 

[ShepherdQ]

Did you miss the whole "experiment was conducted at 55 degrees F" thing?

CO2 does not come out of solution very easily at those temps.

I didn't miss it, but thanks for that. The CO2 did come out, the rod got it down to 300 mg/L after 15 mins, which suggests it would be even more effective at a higher temp.

Listen, as per Dugger's post, if you're vacuum racking and it works and isn't time consuming, more power to you. I'm just saying I'm not going to spend 45 mins watching a vacuum pump chug along if a rod works in 10-15.

 

[Putterrr]

I didn't miss it, but thanks for that. The CO2 did come out, the rod got it down to 300 mg/L after 15 mins, which suggests it would be even more effective at a higher temp.

Listen, as per Dugger's post, if you're vacuum racking and it works and isn't time consuming, more power to you. I'm just saying I'm not going to spend 45 mins watching a vacuum pump chug along if a rod works in 10-15.

I also got a vacuum pump after reading this forum and its the best piece of equipment I own. Degassing is a breeze and racking only takes 6 minutes.

45 minutes after starting my racking/degassing process, you will find me sitting on the couch enjoying a nice glass of wine. Everything is done, cleaned and put away for the next time. Get a pump and you wont look back.

cheers

 

[dpambianchi]

All very interesting comments. Let me address them.

Personally, I never degas wine because 1) I make wine for aging, and so, the CO2 dissipates on its own with processing and time, and 2) I want to minimize any negative impact. Like it or not, degas has some negative impact.

My cellar/winemaking area is at 13C/55F, so that's the temperature of the experiment. That is my typical scenario. Granted that most home winemakers work at much higher temperatures or bring up the temp for degassing. So the experiment should be repeated for, say, 20C/68F.

Re. temperature, let's keep some points/conclusions in mind. The results are not a one-size-fits-all. You decide how to degas depending on your objectives and the results I've presented.

Yes, more O2 dissolves at colder temperature, but less volatile aromas are volatilized, so the stirring rod is better at lower temp though you have to be careful not to over-stir and exceed the limit of acceptable dissolved O2. If you don't care about these points, then sure, the Gas Getter or vacuum pump are better.

Drill rpm is definitely a factor and I stated I did (could) not measure that.

I did not expect different behavior between the Gas Getter and vacuum pump but I wanted to characterize both anyways. From a practical perspective, the Gas Getter needs a big compressor (at least 2 HP) while a small vacuum pump did the same job.

And yes, there are many other test combinations and permutations that should be characterized, e.g. degassing with and without rocking the carboy. I took a first step in understanding the behavior of these devices. Now we need to repeat the tests at different temperatures, different combinations, etc.

Daniel Pambianchi

 

[BobF]

Daniel - thanks for stopping by and clarifying. Love your book.

I hope you'll be sticking around!

 

[dpambianchi]

Daniel - thanks for stopping by and clarifying. Love your book.

I hope you'll be sticking around!

Thank you, Bob.

Life has been hectic and so it's hard to participate actively. There are so many forums and what not.

I have a small commercial winery operation to run and I'm working on a wine chemistry book that's consuming all my time.

P.S. This book is more of a textbook with some very intense chemistry. It's geared to enologist wannabes -- it's not geared to home winemakers.

Happy 2013.

 

[Pumpkinman]

Daniel, I agree, thanks for stopping by!! Your books are a constant reference, and my Wine Making "Bible".
Thanks for all that you do!

 

[GreginND]

I have a small commercial winery operation to run and I'm working on a wine chemistry book that's consuming all my time.

P.S. This book is more of a textbook with some very intense chemistry. It's geared to enologist wannabes -- it's not geared to home winemakers.

Happy 2013.

Sounds like just the book for me!