What triggers the second fermentation in a traditional Champagne bottle?

• A. Liqueur de tirage added at bottling.
• B. Injection of CO2.
• C. Natural fermentation occurs after removing cap.
• D. Exposing to air during aging.

Answer: (A)

In traditional Champagne production, the second fermentation is triggered inside the bottle by adding liqueur de tirage. This mixture provides yeast and extra sugar right before bottling. Once the bottle is sealed, the yeast ferments the added sugar, producing alcohol and carbon dioxide. The CO2 cannot escape, so it stays dissolved in the wine, creating the characteristic bubbles as the wine ages on the lees. Injecting CO2 would carbonate the wine outside the bottle, exposing to air during aging would cause oxidation rather than carbonation, and waiting for fermentation after removing the cap wouldn’t confine the CO2 in the bottle. The tirage step is what starts the second fermentation in the bottle.