Copper is used to treat wines with hydrogen sulfides, aka rotten egg smell. As opposed to sulphur dioxide, which I think would be unaffected by copper.
Its too early for me to think about chemistry though, so correct me if I’m wrong…
Another HUGE factor in a quicker than normal evolution in all wines is the level of dissolved oxygen at bottling. If a wine is held in a more ‘reductive’ state over time, there will tend to be more DO in the wine since it has not had a chance to be released during the process. Due to this, SO2 levels are bottling will be reduced faster than normal and a wine will ‘age’ faster.
Now if DO levels are really low and you have higher than normal levels of SO2 at bottling, and if pH levels are low, that SO2 will tend to hang around longer - which certainly could lead to ‘off aromas’ if the wine is consumed young or note allowed to aerate enough.
Yep, even though wine has been made for a heck of a long time, it is, after all, a pretty fragile product and we continue to learn new things about it each and every day!!!
Cheers!
This new “push” for less reductive/sulfured wines will not end well given an already difficult situation with premature oxidation. I think Leflaive has taken the bait with this as has Lafon. Hopefully my usual customary folks won’t take this bait.
The list of reductive makers will give you a hint. They have low problems with premox.
To me this whole article hints at giving up on aging white burgundy. Just my two cents.
But there’s plenty of Chardonnay made OUTSIDE of burgundy that ages ten years easy and is NOT overtly reductive / sulphured. How come?
I think this is right, it is more than just the SO2 added, but also the extent to which the fermenting wine sees oxygen. So anaerobic bottling lines should help as well.
But beyond that, the containers used for fermentation could make a bigger difference than some people will acknowledge. I don’t think it is just the use of new oak, but perhaps of any kind of oak barrel (new or old) that allows the ingress of oxygen over the extended fermentation period. It turns out that the new Fevre regime that started in 2000 eschewed the use of new oak, but they still use old oak barrels, especially in the Grand Cru. So I wonder if this is part of the problem there, especially with the disastrous 2002 (and almost as bad, 2004) vintage. By comparison, 2002 Brocard Chablis (e.g., the Clos) that were fermented in stainless steel also showed beautifully.
As with any of these cases, it is going to depend on the relative amounts of reductant (sulfur) and oxidants (primarily oxygen). So presumably a strictly anaerobic fermentation and bottling line might allow one to get away with less sulfur.
Different raw material.
Premox outside Burgundy still happens however and with some frequency. Just ask someone who collects Kistler Chardonnay.
Don - of course it happens outside Burgundy, but what seems so odd to me is the frequency differential. I have had a lot of 7+ year (often much older) NZ and Oz Chardonnay, with hardly and premox. If we posit that the higher frequency in Burgundy is related to “raw materials” then changing winemaking, bottling and closures etc would not make sense as a way of addressing it. And if it were raw materials (vineyard work?) then I would expect ALL of any one case to be similarly affected. Has anyone actually assessed what the key differences are between “Burgundian” and “New World” practices?
I don’t think they are the same thing, but what do I know. Reductive winemaking allows for the formation of sulfur related compounds during fermentation when less oxygen is available. When in reasonable amounts, it results in the attractive coffee, creosote, smoky type stuff you find in coche style wines. These compounds go away or get less noticeable with the addition of copper-- a penny or copper stick.
(if you let it go too far, you get those awful disulfides that never go away, even with copper).
Adding sulfur dioxide later in the winemaking process doesn’t in my mind result in the same set of compounds, at least as I understand it. (If I don’t know what I’m talking about, then someone please correct me).
Sure, two different things, both sulfur related. Although, those same compounds can also form post-bottling due to SO2 addition, depending on other factors, right? Either way, I don’t see you contradicting my initial statement.
Sure–you’re right. maybe I misinterpreted you. Usually when people talk about sulfur and it’s effect on and presence in wine, I’m thinking sulfur dioxide (and whatever it turns into). when folks are talking about reductive wines and various related characteristics, I’m thinking more complex sulfur containing compounds. Maybe it’s an artificial distinction. that’s why I asked the question. Reductive compounds disappear or get better when you throw a penny in the glass. A wine that is heavily sulfured before bottling doesn’t seem to change much if you toss a penny in.
Does anyone actually have the science between “reduction” and “sulphur”? I thought the copper penny basically works on H2S, and also resultant compounds such as mercaptans. Is there a difference in the S including compounds in bottle whether a wine is made using “reductive” techniques or whether some S is thrown in near the end or as part of bottling?
Screwcap…
There’s an old Jamie Goode article on his website that nicely reviews this issue, but I don’t have the reference at my fingertips.
The copper is reacting with H2S to form copper sulfide. However, in any solution with SO2, there is a certain proportion of H2S ( and vice versa), so normally each are present, even if the oxidation state of the sulfur is different (-2 in the case of sulfide, +4 in the case of sulfur dioxide). Both of these contrast with native sulfur (oxidation state of 0) or the sulfur oxidation state in sulfate (+6). Here the reduction order (from reduced to oxidized) is:
Sulfide (H2S)
Elemental sulfur
Sulfur dioxide
Sulfate
I obviously wasn’t clear, but when I said “sulfur related”, I was referring to sulfur related compounds in general, extending beyond SO2. I agree about the penny thing to an extent, but as has been mentioned, it only works on H2S, not (I believe) other reductive compounds.
My point, which I never really made, so I’m sorry for the confusion was this. In Burgundy, an area very much known for site transparency, site specificity, and expression of terroir being of the utmost importance, I find it interesting that a couple of the generally most well-regarded producers (of whites) impart such a strong winemaking signature on their wines. Before the Burgheads form a mob and meet up in Massachusetts, I will say that I don’t think it necessarily makes their wines not great, and that I think some reductively handled white Burgundies that I’ve had truly are great. Still, why not allow for a bit more air exposure to allow site expression to take the front seat? Maybe fans will say it still does. Maybe they’re right, but I think a compelling argument can be made on either side of that one.