Dissolved CO2 in Austrian & Other White Wines??

One of the things I’ve observed in some Austrian, some Calif, some Italian, and other white wines is a noticeable presence of dissolved CO2.
Supposedly it is to give the wine a “liveliness” on the palate that it might not otherwise have.

It often has a telltale sign:

1. The screwtop “pops” a bit when you open it.
2. When you pour the wines into your glass, you see this cloud of tiny/tiny bubbles (unlike a sparkling wine where the bubbles
   continue to stream upward) that rapidly dissipate, agglomerating into larger bubbles that form on the surface against the edge of the glass.
   Oftentimes, these swirling cloud patterns can be somewhat mesmerizing to watch.

It’s a winemaking technique that is achieved in two ways:

1. Addition of CO2 directly to the wine just afore bottling to “refresh” the wine, or
2. Treating the wine in such a way to retain the dissolved CO2 left over from fermentation, presumable by
   keeping it under pressure in a tank.

Is one way preferred/better than the other for retaining dissolved CO2?? Obviously, we know which technique
is more “natural”, that CO2 from retained fermentation is somehow “better” than added CO2.

I find, in many cases, that this dissolved CO2 gives the wine an ersatz acidity. That once the CO2 leaves the wine rapidly on the palate,
that “acidity” is no longer there and the wine finishes short. Leaving behind a somewhat vapid wine. I’m just not finding a lot of these
wines I care much for on the palate.
Anyone else noticing this to be an increasing trend in whites??

At a tasting of Austrian wines on Saturday, we had a low-end ($32, compared to their usual $80) Veyder-Malberg Gruner Liebedich '16,
apparently one of the “cult” wines from Austria. It, to me, clearly had dissolved CO2, something nobody else was picking up on until
I pointed it out. The aromas on this wine were perfectly fine. But on the palate, it seemed rather shallow & vapid and didn’t have much
in the way of a finish. Even at $20/btl, I would not buy that wine, even if it is a “cult” wine.

I pointed out that using dissolved CO2 in whites, either added at bottling, or retrained from fermentation, is a technique that seems to be
coming more common in white wines. One of the attendees and a wine authority from NYC, immediately jumped on my claim and that
it is forbidden to add CO2 at bottling, but it was allowed to retain dissolved CO2 from fermentation, a so-called “tank” wine. She did
acknowledge that there was definitely dissolved CO2 in the wine, but that it didn’t detract from the wines quality, to her palate.
Does anyone know if, in Austria, they are allowed to add CO2 at bottling to “freshen” the wine, or that it is absolutely forbidden??
That only “tank” wines are allowed. I’ve not been able to find anything on the Net specifically addressing this issue vis a vis dissolved CO2.

Tom
And, no, David…this is not a or a troll, just sorta curious.

As you probably know, it’s also quite common in German wines, though I think most often in sweet wines. I have no problem with it in most cases. It can give wine some zip, like acid does.

I think it’s most common in wines that aren’t moved around a lot from barrel to barrel or tank to tank. So it may be an incidental byproduct of the winemaking in a lot of cases.

Back in the day, Terry Theise made a wisecrack about a Mosel competitor who was probably adding C02 to his wines, which I think was a shot across the bow to Rudi Wiest & Manfred Prum.

Nowadays, I’d support just about any technique which can help keep a white wine from prem-oxing, and if some spritz in the wine helps to keep it fresh, then bring on the spritz.

Common result of reductive winemaking. Been around for eons. Surprised that the guy who has followed everything from the very start thinks it’s a new trend.

Yup, John…that’s probably the case.
A year ago, when we had the newly arrived IngridGroiss GV '16, I noticed a bit of dissolved CO2 in the wine. When I asked her, she acknowledged there was a bit
of dissolved CO2 left over from fermentation. It didn’t particularly detract from the wine. A few month later, when I tried it again, I could not pick up any dissolved CO2
and the wine seemed at her customary high standards.
We tried last week her newly-arrive '17 GV & GS & I could not pick up any dissolved CO2.
Tom

Well, David…it certainly has been around for a long time. But it just seems to me that I’m seeing more & more whites that have dissolved CO2.
Which is what I would call a growing trend. But, maybe, I’m just becoming more aware of dissolved CO2 than I had been before.
Tom

Not that uncommon in Red Burgundy - Fourrier famously.

More folks doing reductive winemaking? Improved closures causing the CO2 to be retained? I really do not see it as an increasing trend, but I also drink way more German and Austrian wine than most people.

Tom,

Most of the Italian white wines I import are bottled in the spring or early summer following the vintage, and retain some CO2. It isn’t necessary to add it, it’s entirely natural. I like it. I understand that it can be removed by sparging the wine with nitrogen, but that sparging also removes some aromas. Maybe some producers add CO2 but I can’t imagine why it would be necessary, as fermentation produces so much of it anyway.

Perhaps a winemaker could chime in here…

Hmmmm, Oliver…I don’t recall any of your whites that seemed to have dissolved CO2 in them. But, then, maybe I wasn’t
paying as close attention as I do now? I look very closely now for that tell-tail cloudy swirl of tiny bubbles as they agglomerate
into bigger bubbles.
I understand that there are some producers that do add CO2 at bottling.
Tom

Which ones Tom?

Don’t know any names, David. But I’ve read in several articles that adding CO2 a bttling is a procedure that is
gaining favor. In Calif wines, I mostly get it in Rieslings.
Tom

Hi,

CO2 is often used as an inerting blanket in place of Nitrogen (more effective as its heavier than O2) and Argon, which it is quite a bit cheaper than (Argon is also not allowed in USA for Organic processing). CO2 can leave a tell tale spritz as a portion of it will dissolve in the wine. The beneficial aspect to that, from my understanding, is that it reduces the ability of the wine to absorb oxygen, by changing the ratio of dissolved gasses (both in winery and later in bottle) effectively increasing its ability to age and preserving its freshness, especially during the bottling process. A LOT of aromatic whites and roses in the market have higher levels, my guess would be that as most of these are bottled less than 6 months after harvest and a portion of the CO2 is retained from fermentation, but it also would be possible (and probable) that CO2 is used in transfers/inerting as opposed to N2 leading to higher levels in the bottled wine. How much of this is a target of winemaker wanting it to be a touch spritzy vs. winemaker wanting to avoid oxidation is another matter of debate.

Regards,
Brian Maloney
DeLoach and Buena Vista

I should also point out that leaving residual CO2 in wine is not a ‘treatment’, it’s the absence of a treatment; you can get rid of it by sparging with nitrogen, but that (I hear) also tends to strip some aromas.

I drink/taste a fair amount of Austrian wines, but can’t say I’ve noticed this. I like Oliver’s possible explanation, for producers who bottle earlier where CO2 left from fermentation may not have dissipated completely.

But another possibility is that there are more than a few winemakers who believe (mistakenly, IMO) that CO2 acts as a preservative, and protector against oxidation. I believe some actively introduce CO2 at bottling for this purpose.

Alan,

Wouldn’t higher than normal levels of dissolved CO2 tend to reduce the amount of absorbed oxygen, though? I have heard that you can use less SO2 if you have some CO2 in the wine, don’t know if that’s true.

Thanks, Brian…that’s exactly the kind of information I was looking for.
On whites that are bttld within a few months of fermentation completion…do winemakers routinely keep track
of the dissolved CO2 levels in the wine??
Tom

Next time you open a screw-topped Austrian white…listen for the “pop”. Then look for this cloud of tiny/tiny
bubbles when you pour the wine that dissipates rapidly.
Tom

Some do, some don’t.

Names. Names, or it’s just hearsay.