Reduction (wine) describes aromas that can develop when wine is made or stored under conditions with limited oxygen exposure. These aromas are often associated with volatile sulphur compounds and may include struck match, flint, rubber, cooked egg, cabbage, onion or other sulphurous notes. A light reductive character can be intentional or acceptable in some wines; strong, persistent unpleasant aromas are generally considered a fault.
Reduction can arise during fermentation, lees ageing, bottling or storage when yeast metabolism and low-oxygen conditions favour the formation or retention of sulphur compounds. The exact compounds and their sensory thresholds vary. Some wines are deliberately protected from oxygen to preserve freshness, but this approach requires careful control.
Common descriptors include struck match, flint, rubber, rotten egg, cooked cabbage and onion. Some aromas may dissipate after swirling or decanting, while others remain. Not every smoky or mineral note is reduction; the intensity, persistence and overall balance of the wine matter.
Reduction is associated with limited oxygen and sulphur-related aromas. Oxidation occurs when wine is exposed to too much oxygen, often causing browning, bruised-apple aromas and loss of freshness. They are different processes and produce different sensory effects.
Example: a young white Burgundy may show a light struck-match note that becomes less noticeable with air, while strong rotten-egg aromas that persist can indicate a fault.
Chef’s note: a brief period of aeration may help some reductive aromas dissipate, but decanting does not reliably correct every reduction fault. Taste before deciding how to serve the wine.
This term is one of hundreds covered in depth across OCS courses, learning paths, and 1-on-1 coaching with Chef Eric.
