Dissolved CO2 in Wine??

I've heard of several references of winemakers adding/dissolving CO2 in white wines to brighten them up afore bottling. Yet I've not encountered any that seemed fizzy on the palate.
Can anyone tell me how common this practice is and how do they go about getting the dissolved CO2 into the wine? Add an Efferdent tablet???
Tom

[David M. Bueker]

Adding it?

There's a lot of German Rieslings that have a bit of dissolved CO2. They have a bit of spritz on the palate when young. It happens naturally though.

Adding it?
There's a lot of German Rieslings that have a bit of dissolved CO2. They have a bit of spritz on the palate when young. It happens naturally though.

Mostly I've heard of it w.r.t. German Rieslings, David. And Oz Rieslings as well. Presumably the dissolved CO2 comes from the fermentation.
Do they do anything to intentionally retain the dissolved CO2 after the fermentation is completed?
Tom

[David M. Bueker]

Not that I know of Tom. Remember that German Rieslings are bottled very soon after fermentation & throwing of tartrates, so there's not a lot of time for residual CO2 to go away. I think it's just that - a product of speed.

CO2 is often added to wine in Germany before bottling. It can be added in a variety of ways using a tank of compressed Carbon Dioxide and a simple hose, or with a tank fitting that will inject the CO2 along with wine that is being racked. Since stainless steel can be sealed and chilled, the CO2 will stay in solution for a few days prior to bottling. It must not be added too fast, or the foam that breaks the surface of the wine will carry away some of the aroma as well. The added CO2 is used to enliven the wine and make it fresher tasting in its youth. In fact, a wine with CO2 added will taste drier and less obviously fruity and must be used judiciously (or not at all) with highly aromatic varieties.

Another use of compressed Carbon Dioxide is to blanket wine as protection from oxidation (if, for example the tank is not completely full), though Nitrogen is a better option.

CO2 is of course, a product of fermentation and reductively made wines do retain some of that natural CO2, but adding it is a very common practice to ‘tweak’ the finished product and is especially useful under screw-cap.

Cheers,
Bill

Many Italian whites have noticeable CO2 when first opened, particularly when they first arrive here a few months after bottling. I've never heard of it being added in Italy, though, it's residual from fermentation. Apparently you can get rid of it by bubbling nitrogen through the wine, but why?

I've even had US Pinot Noir that had a noticeable 'bead' around the edge of the glass when first poured.

[David M. Bueker]

Bill,

Do you believe that the top German producers add CO2? I've never heard of it from that echelon.

Because they don't tell you doesn't mean they don't do it. I'm aware of it in Australia and New Zealand, and yet not one producer has ever volunteered that they dissolve CO2 into their rieslings.

Many Italian whites have noticeable CO2 when first opened, particularly when they first arrive here a few months after bottling. I've never heard of it being added in Italy, though, it's residual from fermentation. Apparently you can get rid of it by bubbling nitrogen through the wine, but why?

I've even had US Pinot Noir that had a noticeable 'bead' around the edge of the glass when first poured.

Oliver,
The traditional way of reducing or eliminating dissolved CO2 in wine was and is racking. I'm sure that more technically-minded folk could sparge with nitrogen, but (as you said) why?

Mark Lipton

[David M. Bueker]

Because they don't tell you doesn't mean they don't do it. I'm aware of it in Australia and New Zealand, and yet not one producer has ever volunteered that they dissolve CO2 into their rieslings.

And there's no hard evidence that they did either.

Name names or don't insinuate is all I am saying.

I hate these discussions for this very reason.

Another use of compressed Carbon Dioxide is to blanket wine as protection from oxidation (if, for example the tank is not completely full), though Nitrogen is a better option.

As you say, CO2 is generally not the best gas for this application, since unlike Riesling, many wines don't benefit from the dissolved CO2 that results. Argon is also widely used, better at this function than nitrogen although also pricier.

Gasses are more soluble in water at lower temperatures. Have you ever put a cold glass of water on your bedstand before sleep? When you wake up later, you will notice that as the water warms the dissolved gasses (air, mostly) have formed bubbles.

Places that do long, cool fermentations will wind up with aqueous solutions saturated (i.e. holding the maximum amount soluble) with CO2. If bottled without too much disruption, the wine would then be supersaturated at warmer temperatures and this might lead to a slight spritz. I wonder if this gets exacerbated by cold stabilization (perhaps under a protective CO2 layer) just prior to bottling?

Hi Tom and others,
Here’s some interesting reading;

Use of Inert Gases by Murli Dharmadhikari
http://www.extension.iastate.edu/NR/rdo ... gases1.pdf

Salute

Many Italian whites have noticeable CO2 when first opened, particularly when they first arrive here a few months after bottling. I've never heard of it being added in Italy, though, it's residual from fermentation. Apparently you can get rid of it by bubbling nitrogen through the wine, but why?

I've even had US Pinot Noir that had a noticeable 'bead' around the edge of the glass when first poured.

Oliver,
The traditional way of reducing or eliminating dissolved CO2 in wine was and is racking. I'm sure that more technically-minded folk could sparge with nitrogen, but (as you said) why?

Mark Lipton

Well yes, as long as you don't mind the wine being exposed to oxygen, ie not for most whites.

There's some stuff on the internet about adding CO2, which I found interesting, but with cold-fermented, early-bottled wines I'm not sure why you'd have to.

Another use of compressed Carbon Dioxide is to blanket wine as protection from oxidation (if, for example the tank is not completely full), though Nitrogen is a better option.

As you say, CO2 is generally not the best gas for this application, since unlike Riesling, many wines don't benefit from the dissolved CO2 that results. Argon is also widely used, better at this function than nitrogen although also pricier.

Whether argon is better depends on what you're trying to achieve, Mark. Argon is heavier than air, so doesn't diffuse out of the bottle very quickly. OTOH, if what you want to do is to replace dissolved oxygen in wine with an inert gas, the best gases for the job are helium and neon. As I've written here earlier, though, if you want to efficiently replace a dissolved gas in wine, you're going to have to bubble it through the wine or do a freeze-pump-thaw cycle, which no sane winemaker would subject his wine to.

Mark Lipton

Another use of compressed Carbon Dioxide is to blanket wine as protection from oxidation (if, for example the tank is not completely full), though Nitrogen is a better option.

As you say, CO2 is generally not the best gas for this application, since unlike Riesling, many wines don't benefit from the dissolved CO2 that results. Argon is also widely used, better at this function than nitrogen although also pricier.

Whether argon is better depends on what you're trying to achieve, Mark. Argon is heavier than air, so doesn't diffuse out of the bottle very quickly. OTOH, if what you want to do is to replace dissolved oxygen in wine with an inert gas, the best gases for the job are helium and neon. As I've written here earlier, though, if you want to efficiently replace a dissolved gas in wine, you're going to have to bubble it through the wine or do a freeze-pump-thaw cycle, which no sane winemaker would subject his wine to.

Mark Lipton

Mark, I wasn't referring to the situation in the bottle but rather responding to Bill's comment about using nitrogen in the tank as a "blanket" to prevent oxidation. In that application, argon provides a more effective blanket than nitrogen by virtue of its density and doesn't have CO2's issues in terms of dissolving in the wine.

Because they don't tell you doesn't mean they don't do it. I'm aware of it in Australia and New Zealand, and yet not one producer has ever volunteered that they dissolve CO2 into their rieslings.

And there's no hard evidence that they did either.

Name names or don't insinuate is all I am saying.

I hate these discussions for this very reason.

Hi David,

I guess I’m a little surprised by your reaction. What good would it do to know? Just because Dr. J.J. Müller added a little CO2 before bottling on the 2007 Schloßberger Riesling Kabinett Feinherb Liter is no reason to ‘out’ them as cheaters on the internet. If one took two bottlings, identical in every other way, one with high-side naturally produced CO2 and one with tank added CO2, it would be next to impossible to distinguish the two. Either way, it will likely be completely undetectable after a year or so of cellaring (at least under cork.) Furthermore, there are dozens of more extreme measures that can be taken by a Weingut to manipulate wine, I would cite acidification/deacidification, cultured yeast inoculation, and enzyme additions as far more interventionist, all of which are practiced by upper-echelon producers and without much objection by the wine-loving public. My very favorite wines made throughout the world, not just in Germany, tend to be from producers who make wines with almost zero intervention (we could debate what that means, I guess. Maybe on a different thread ) and I personally wouldn’t endorse adding CO2 to a wine on general principle, but it is legal, relatively harmless, and up to the discretion of the producer who is trying to turn out the best wine he thinks he can.

Cheers,
Bill

[David M. Bueker]

Bill,

It's exactly because many would treat the whole industry as "cheaters." I don't really care what a specific producer does, but every time one of these threads gets started (more so on other sites than here, but still...) it becomes the old "well so and so does it, so everybody else who denies it must be lying." Then there's the collateral damage due to producers (rightly or not) being perceived as manipulators.

Drives me nuts.

Because they don't tell you doesn't mean they don't do it. I'm aware of it in Australia and New Zealand, and yet not one producer has ever volunteered that they dissolve CO2 into their rieslings.

And there's no hard evidence that they did either.

Name names or don't insinuate is all I am saying.

I hate these discussions for this very reason.

With respect David, I said I was aware of it. To put that beyond doubt, I know, for a fact, that it happens.

I feel no obligation to name names, as I don't hold the view that CO2 addition is cheating in any way.

[David M. Bueker]

No names=no evidence.

Sorry, don't buy it.

Related to the original topic of the thread - With re sparkling wines there are those made by the methode champenoise, others made by the charmat method and others made, as are soft drinks, by injecting carbon dioxide into the wine.

Because they don't tell you doesn't mean they don't do it. I'm aware of it in Australia and New Zealand, and yet not one producer has ever volunteered that they dissolve CO2 into their rieslings.

And there's no hard evidence that they did either.

Name names or don't insinuate is all I am saying.

I hate these discussions for this very reason.

With respect David, I said I was aware of it. To put that beyond doubt, I know, for a fact, that it happens.

I feel no obligation to name names, as I don't hold the view that CO2 addition is cheating in any way.

Andrew,

do you happen to know how the initial 'charge' of CO2 dissipates in the wines you're referring to? I am curious because in my area (I import Italian wine) there's always quite a bit residual at bottling (enough to be visible, in any case).

All depends Oliver, on the concentration or level of gas dissolved in the liquid, temperature and “pressure” inside the bottle, and on how “tight” of a seal the enclosure has on the bottle. Take a bottle of your favorite carbonated drink that is more or less “super saturated”. In the sealed bottle everything more or less should be in “equilibrium”, once the “seal” is broken and bottle unsealed that “equilibrium” is altered. Depending upon the temperature and the exposed surface area of liquid will determine how long it takes before that drink becomes “flat”.

Salute

CO2, which as we all know is a by-product of fermentation, is present in all wines during production. Many wine makers put the wines through steps that will reduce the amount. Some apply vacuum to the wines. The turbulence of pumps will dissipate much of the CO2 as well as filtering and bottling. Home wine makers who use kits (wines made from concentrated grape juice) seem to have a greater problem with dissolved CO2 and the directions even include a de-gassing step, which involves stirring the wine vigorously for several minutes. I don't know why wines from concentrates would be more prone to dissolved CO2. If a wine is treated very gently during production (from fermentation through bottling), it may very well have a CO2 spritz in the bottle. As others have pointed out, in some wines this is desirable. However, it should not be confused with a wine that has some sort of bacterial fermentation, such as malo-lactic, take place in the bottle. These will be fizzy, have a funky smell and is considered a fault.