What is the name of a six-litre Champagne bottle?

A six-litre Champagne bottle is called a Methuselah.

A Methuselah holds the equivalent of eight standard 750-millilitre bottles. Its name comes from Methuselah, a biblical figure traditionally said to have lived for 969 years, making it part of Champagne’s elaborate biblical naming system for large bottles.

Champagne bottle sizes are often confused because several names sound similar and their capacities rise quickly. A Jeroboam holds three litres, a Rehoboam 4.5 litres, a Methuselah six litres, a Salmanazar nine litres, and a Balthazar 12 litres. The 15-litre Nebuchadnezzar is larger still.

Large bottles are valued for celebrations and presentation, but they also mature differently because the wine has a lower ratio of oxygen exposure to volume. Their weight and fragility make them less convenient to handle than ordinary bottles.