Article produced with permission from Wine Searcher

“We’re not talking about reduction here, we’re talking about a wine that is reduced.”

Professor Gilles Revel, one of the most eminent teachers at Bordeaux’s oenology department, has lost about half of his students attending his tasting class at this point. But he carries on regardless, trying to illuminate a point that is key to understanding not only potential faults in wine, but also the process of making fine wine in the first place.

Let’s get the simple bit out of the way. The term “reduced” is pretty much invariably referring to a wine fault. “Reduction,” on the other hand, is about the process of winemaking in a reductive (i.e. oxygen-free) environment, as opposed to one that uses oxygen as part of the process.

Working out what exactly comprises good or bad reduction is, however, an area that causes plenty of confusion. Richard Bampfield MW suggests that, “it’s a semantic issue in many ways – many people simply refer to good or bad reduction.”

What we can reasonably infer is that oxygen has both good and bad points when it comes to winemaking. Oxidation is what you can clearly see if you leave a glass of wine in the kitchen for a day or two and watch the color change, turning russet then brown. If a restaurant serves you a bottle of young sauvignon blanc that is already going brown even though it’s only a year old, you can pretty much guarantee that the cause is oxidation.

But using oxygen during winemaking is also a specific technique essential in the production of, for example, sherry, Madeira, certain types of port, and “vin jaune” from Jura. In the same way that reduction is “a semantic issue,” these wine styles shouldn’t be called oxidized, but oxidative …