Champagne wine exclusively comes from black grapes such as Pinot Noir. The pressing must be done immediately after picking. The white wine thus obtained, called vin clair (clear wine), is conserved for at least five to six months. The tirage (bottling) happens before provoking a new fermentation that generates the famous bubbles. The production would then be sold in the following 15 months to three years. The Maison Collet domain, however, also works from closely guarded fabrication secrets. Its cellars contain bottles dating from its creation in 1921.