I would say, in Germany, rarely. I think to be truly considered pre-mox you need a younger wine say under 10 years of age to call it premox. Some rieslings just don’t age well because of vintage or other problems.
A somewhat related observation is that it is extremely difficult to make non SO2 natural wine because Riesling is a grape that oxidizes quickly. A Natural winemaker in Germany I know said he has conducted many no SO2 trials with a variety of grapes and riesling oxidizes the quickest and interestingly he will not make a no SO2 Riesling.
If we assume this to be true then I would expect a higher amount of premox wines but yet I rarely, if ever, encounter them from Germany.
Is premox already understood? To my knowledge it isn’t, but I’d be glad to be pointed towards studies that have conclusively shown what’s going on. I lost my complete 1996 vintage of white burgs to that, and since have never returned to buying such wine for long-term maturation…
Possibly related to that, Riesling has a very low content of flavanoids, the lowest of all white-wine grapes IIRC, making its aromas extremely stable to oxidation when conventionally bottled (i.e. with SO2). In this context, I don’t know how to place the wine producer’s comment re: fragility of Riesling against oxidation. Could you elaborate? The virtually complete lack of premox’ed (or even maturely oxidized) dry Rieslings across the board (Alsace, Germany, Austria) contradicts the hypothesis that Riesling was particulalry prone to oxidation.
What Riesling (as all white wines) does sometimes show, is the untypical aging note (“unytpische Alterungsnote”) that occurs when vines experience significant drought stress and that condition isn’t mitigated in the cellar. The wine develops notes of mothballs and chemical detergent, and does so very early on. But the last time I saw that in wines of the quality level we here are interested in, was in the 2003 vintage in German Rieslings.
Are you ignoring the rampant premox at Trimbach from 1997-2000 (some also say 2001, but I haven’t seen it as a general issue), as well as the disaster of late 1990s and early 2000s from Kreydenweiss?
What he told me is that he has done no SO2 trials with Riesling, Silvaner, Müller-Thurgau, among others and Riesling browned the quickest and in his view is not a good candidate for making a no SO2 wiine. I have also noticed I just don’t like most no SO2 Rieslings.
As I recall, sugar is a pretty potent antioxidant. Certainly, sweet wines last a long time even at room temperature.
(When I worked in the darkroom department of a camera store in college, a colleague pointed out that a bit of sugar would keep your Dektol print developer from oxidizing. Normally Dektol would turn black if you left it out overnight. Of course, there was a risk that your prints might be sticky if you didn’t rinse them thoroughly. )
Something in another thread reminded me that JJ Christoffel had some oxidation issues with one or two lower-level Pradikats in 01 or 02 where they bottled some with a plastic closure. I guess that shows that riesling can oxidize with an unreliable seal.