Some may argue that reductiveness is a flaw and some may argue that it doesn't matter. Personally, although my nose is super sensitive to it, I would rather pop a bottle and find out it's a little farty than drink a wine with way too much new oak. At least the reductiveness will blow off fairly quickly allowing the rest of the aromas to shine through.
Whether minimal intervention winemakers are adding trace amounts of sulfur to their wines or not, many natural wines are prone to flaws and faults. With minimal to no preservatives (sulfites) in natural wines, you would think that most bottles are prone to oxidized faults like mouse rather than reduced faults that create off-putting sulfuric aromas like burnt rubber and bad cabbage.
Before diving into the many reasons why natural wines may display reductive notes, let's go over some simple vocabulary...
- Oxidation- when a wine was intentionally exposed to oxygen (i.e. sherry, Madeira, certain types of port, and "vin jaune" from Jura). These are wines that are OXIDATIVE not OXIDIZED.
- Oxidized- a wine has interacted with too much oxygen and is at the point of no return. This is a fault. When the wine has essentially aged so rapidly that it has basically (and unintentionally) become vinegar.
- Oxidative- when a wine is simply displaying notes that come from interaction with oxygen (almonds, browned apple/pear, marzipan, general nuttiness, etc.)
- Reduction- the process of winemaking in an oxygen-free environment, as opposed to one that uses oxygen as part of the process; sealed stainless steel tank (no oxygen interacting with the wine) vs oak barrels (oxygen can creep through... barrels are water-tight, not air-tight)
- Reduced- this is referring to a wine fault where the wine did not receive enough oxygen during production and is deemed a fault. Aromas of burnt rubber and bad cabbage.
- Reductive- displaying subtle notes of reduction... flint, struck-match, rotten eggs, weird farts
So reduction and oxidation are opposites.
- Reduction = without presence of oxygen
- Oxidation = with presence of oxygen