Deep in the cellars at Bollinger, securely locked behind iron gates, is a remarkable library of the famous champagne house’s oldest vintages.

There are precious bottles of the 1952, the first RD – recently disgorged – champagne, released by Madame Lily Bollinger in 1967. Magnums and jeroboams from vintages stretching back through the 20th century and into 19th. And there, in a special extra-secure section at the very back of the cellar, the last remaining bottles of the 1830 vintage, discovered in a forgotten corner of the cellars in 2010. The wine was made the year after the company was founded.