Reductive winemaking techniques protect the juice and wine from oxygen. This is usually done to maintain the fresh fruit characters associated with the grapes (for example, the bright herbaceous and tropical notes of Sauvignon Blanc). Reductive winemaking is the opposite of oxidative winemaking.
Approaches that are reductive include using air-tight vessels (for example, stainless steel tanks rather than oak), as well as avoiding techniques such as bâtonnage or racking, which can expose a wine to oxygen.
Reductive winemaking can lead to reductive or reduced characters appearing in the finished product – these include rotten egg gas (hydrogen disulphide), struck match, or notes of onion and garlic.
