Which method is used to remove dissolved oxygen pre-bottling?

• A. Flushing with inert gas (sparging)
• B. O2 can accelerate aging
• C. Vacuum degassing after fermentation
• D. Adding sugar to bind oxygen

Answer: (A)

Dissolved oxygen in wine promotes oxidation, so the most effective pre-bottling step is to create an inert environment and push out oxygen. Flushing with inert gas, or sparging, uses gases like nitrogen or argon that don’t react with the wine. By flowing this gas through the wine or across the surface during filling, oxygen is displaced and the headspace is filled with an oxygen-free blanket. When the bottle is filled and sealed, there's far less oxygen available to enter, which slows oxidative aging and helps preserve aroma and color.

The other statements aren’t methods to reduce dissolved oxygen. Oxygen accelerates aging, but that’s an effect, not a method. Vacuum degassing after fermentation targets removing dissolved gases and volatiles, not specifically preventing oxygen pickup during bottling. Adding sugar does not bind oxygen to remove it from the wine.