In its simplest sense, cuvée refers to an individual blend or style that the winemaker is expressing. However, in Champagne, cuvée means something more, hence the general confusion around the terms. In Champagne, technically it refers to the juice extracted during the pressing of the grapes from which the highest quality juice is extracted. From a 4000kg batch of grapes this would be the first 2050 litres of juice.
The remaining juice is technically referred to as the ‘tailles’ meaning the coarser, inferior juice from the press that doesn’t form the cuvée. Only a few less conventional Champagne makers use the Tailles. Most of the tailles form the base juice for lower grade Champagnes or in some cases, sold to other wine makers in the production of vin mousseux or Crémant.
The quality of the Cuvée can still be compromised by the way the grapes are pressed. Traditionally, they are heaped into a mound inside a wooden basket press. Nowadays, membrane pneumatic presses are used to achieve the same result in a less oxidative environment with a higher degree of control.