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Oxidised or Oxidative?

I’ve been trying to get my head around the terms "oxidative" and "oxidised" recently, and specifically how they relate to one another. It stems from something I read some time ago, ascribed to Thierry Puzelat if I remember correctly, concerning his angst that many people who taste his wines and write them off as oxidised can’t tell the difference between an "oxidative" style and a wine which is oxidised. I’m afraid I can’t remember where I read it – a quick Google didn’t turn it up again, but if you know the article I am referring to do let me know.

First up, off the top of my head, a quick recap. Wines can be made in oxidative or reductive styles. Because yeasts ferment wine under anaerobic conditions they generate lots of unusual and smelly compounds including hydrogen sulphide and mercaptans which would otherwise be neutralised by oxygen. Don’t switch off, I’m going to keep this simple (I need to so I can understand it!). If the wines were made and bottled without any contact with oxygen at all (unlikely) my understanding is that these compunds would persist in the wine, and we would notice them as soon as we opened the bottle. Because of this (and perhaps for other reasons as well) wines are generally allowed some exposure to oxygen at some point during fermentation and/or élevage – racking is an important example of this, and it can markedly influence how a barrel sample (and ultimately the wine) tastes. Through these processes the wine moves away from the reduced end of the spectrum, nevertheless it doesn’t move too far – on the whole modern winemaking tends towards a reductive rather than oxidative style, as a safety net I think, as many are fearful of oxidation. Some even toy with more overt reduction in their wine; the Vieilles Vignes Santenay I drank last night was one example, and the same matchsticky aroma it possessed could also be found in Michel Chapoutier’s Sélection Parcellaires which I tasted in Tain l’Hermitage last week.

Move in the other direction – increasing or altering the point of exposure to oxygen – and you can move into oxidation. This style of winemaking was once far more prevalent, and is still embodied in a number of styles, Ambre Rivesaltes for instance, Vin Jaune from the Jura, Sherry, Madeira and so on. Oxidative versus reductive methods are also important in determining style in Champagne, with Bollinger the classic oxidative style I think, with many others favouring a reductive style. But, sticking with still wines, modern winemaking values fruit freshness and definition in the mouth over these more slippery oxygen-influenced styles. Hence today, most wine is made with protection from oxygen in mind.

So oxidative styles depend on exposure to oxygen (d’oh!). Which implies that the "oxidative" style and wines that are simply "oxidised" must surely be part of the same spectrum. Control the oxygen, so that it impacts on the style but without influencing it so much that the wine begins to take on the characteristic baked-earth-baked-orange flavour of every other oxidised wine in the world, and you have a wine you can describe as oxidative. Take your eye off the ball, and you have something that resembles Madeira. Delicious wines in their own right, but not necessarily a style or process that suits, for example, the beautifully floral and minerally Chenin Blancs that originate from the Loire Valley.

So where is the cut-off between "oxidative" and "oxidised"? I suspect it is very nebulous, and impossibe to define, a rather grey area on a fading spectrum of style, because I suspect it will differ from one taster to the next. I find the wines of Bollinger to be "oxidative" in style, but I can’t imagine anyone describing them as "oxidised". I think the same of the wines of Juchepie, which move away from the freshness of many other Coteaux du Layons into a deeper, more burnished orange-gold style, and what oxidative trace exists is well hidden by their flavoursome and complex character. Others don’t like the style (they were once described to me as "too oxidative" by a UK wine writer), but I like them very much, whereas I would perhaps tolerate the same character in dry Chenin Blanc less well I think. Perhaps this indicates that my "tolerance" is actually just where I am prepared to draw the line, as it seems that my "tolerance" depends on the style of wine….or perhaps even my "understanding" of the style in question?

Is it the fact that the oxygen-influenced (hedging my bets!) wines of someone like Thierry Puzelat are marked by notes of bruised apples and cider, rather than the overt more "Madeirised" flavours of baked-earth-baked-orange noted above, that he describes them as oxidative rather than oxidised? Ultimately, whether these wines are "oxidative" or oxidised, when the beautifully floral and fresh apple-pear aromas of young Loire Valley Chenin Blanc are replaced by more cidery characteristics, the wine is – in my opinion – ruined by oxygen. Therefore I would cal it not "oxidative", but oxidised. Wines where the style is infuenced, but the wine not oxidised, can be termed "oxidative". But I acknowledge this "understanding" is subjective and dependent upon my personal interpretation of the wine.

Do you think I have got this right? I’m looking not so much for comments on individual wines or winemakers, but on my understanding of oxidative versus oxidation and the point where one crosses into the other? Any comments gratefully received.

5 Responses to “Oxidised or Oxidative?”

  1. Now I know why no one tackles this issue! This is surely the most comprehensive discussion that does not require a background in organic chemistry, and I think you may be on to something with “cider” vs “maderized.”

    Having said that, at our place we say “oxidative” when we think the effect is deliberate, “oxidized” when we think it’s unintentional.

  2. Thanks Wine Mule. There’s no guarantee any of this is correct though, just what I have worked through in my head this week.

    I think the intentional/unintentional distinction is a good one. Although doesn’t that lend some validity to wines which are horrendously oxidised to the point of being undrinkable and yet, because that is the intended style (I’m thinking of really ‘out there’ Loire estates such as Jean-Pierre Robinot) they are “oxidative”?

  3. Interesting topic. Esepcially in the light of the “Vins Naturels” trend that is taking place.
    In particular for the red vins naturels I often have the impression that instead of being individual and carrying a sense of terroir, they resemble much, especially because of oxidation. I’ve had a Gamay from Switzerland that tasted exactly the same than a Gamay from Beaujolais and another one from the Loire, of apple juice and cinnamon.
    So the question is: in which case is this intended and in which not? I suppose that Vins Naturel, should taste like the ones of Marcel Lapierre with typicity that is not covered by oxidation.
    But of course, there are many wines or wine styles that are oxidative that I enjoy. I think I enjoyed drinking Robinot wines for example. Regards.

  4. Thanks Alex. I think the “sameness” of many of these wines is an important point. The characteristics of terroir differ from vineyard to vineyard, and thus wine to wine. Oxidised wines taste…..err…..oxidised.

    I’ve had one or two Lapierre wines…they were very good. Neither “oxidative” nor “oxidised”.

  5. I’m not sure about this part – ” If the wines were made and bottled without any contact with oxygen at all (unlikely) my understanding is that these compunds would persist in the wine, and we would notice them as soon as we opened the bottle.”

    In the winemaking class I am taking they say this:

    First – Another characteristic of a good wine yeast is that it produces minimal off flavors. Minimal off flavors, of course, I think are self-explanatory. We don’t want things like hydrogen sulfide, rotten egg aroma, in the wine and so we want a minimal amount of off flavors produced by this good wine yeast. Finally, our good wine yeast should be SO2 tolerant. Once again, we use SO2 at several steps in wine making and so we would like our wine yeast to be tolerant enough not to be killed by the SO2 that we like to use at several steps during wine making.

    Second – “The last fining I’ll talk about is fining for sulfur and in winemaking we have a number of different types of sulfur. In this case, we’re trying to remove what are called sulfides, which are things like hydrogen sulfide, which is the smell of rotten eggs, or some other sulfides, like ethyl, mercaptan and related chemicals which have a pretty nasty aroma. These are actually generated in very small amounts by the yeast during the fermentation process and when that happens you sometimes need to treat the wine to remove that aroma and copper salts are typically added. So the copper salts react with the sulfides,forming what’s called copper sulfide, which is totally insoluble. That then settles to the bottom of the tank. Again it’s racked off and you have wine now that doesn’t smell like rotten eggs.