From Vine to wine
Pressing centres are very strictly regulated, in line with more than 20 approval criteria that were introduced in 1987. These cover pressing and racking capacity; daily press loads; type of press used; pressing and sulphuring; and hygiene standards.
On arrival at the pressing centre, each delivery of grapes is weighed and recorded. Every 4,000kg ‘marc’ (traditional unit of measurement for a press-load of grapes) is numbered and recorded in the ‘carnet de pressoir’ (pressing logbook), noting details of grape variety, cru and destination (whether to be retained by the winegrower or sold to a Champagne House). The grapes are also tested for compliance with the minimum alcohol content by volume that is specified for the vintage in question.
Juice extraction is strictly limited to 25.5 hectolitres per 4,000kg marc, separating the first pressing juice (the cuvée, representing 20.5hl) from the second (the taille, representing 5hl). Each has quite specific characteristics. The cuvée is the purest juice of the pulp, rich in sugar and acid (tartaric and malic). This produces wines with great finesse, subtle aromas, a refreshing palate and good aging potential. The taille is also rich in sugar, but acid content is lower while mineral content (especially potassium salts) and pigment concentrations are higher. Taille musts produce intensely aromatic wines – fruitier in youth than those made from the cuvee but less age-worthy.
Champagne presses range in capacity from 2,000 to 12,000 kilos of whole grapes. Manually operated, vertical wine presses were standard throughout the region until the late 1980s, and still account for some 28% of plant. The mechanization of the ‘retrousse’ (scooping the edges of the press cake back into the middle after each pressing) then led to the increasing use of horizontal presses with a lateral membrane, angled pressing plates and a rotating press pan. Horizontal presses these days are computer-controlled, with a multi-function operating system.
On arrival at the pressing centre, the date and time the grapes were picked are recorded, as is the vineyard of origin (cru). Each batch is then pressed separately, partly for traceability purposes but also to ensure a homogeneous press load, according to grape variety, vineyard plot or group of similar plots.
Rosé Champagne is made by maceration: leaving destalked black skinned grapes to macerate in a tank prior to pressing until the desired colour is achieved (24-72 hours). .
The approval procedures for pressing centres are part of AOC regulations, in line with quality control requirements covering a broad spectrum of Champagne production processes.
The key approval criteria for pressing are as follows:
Cage washing is compulsory after each press load. As part of the commitment to sustainable viticulture, solid residues that remain after pressing (the ‘aignes’) are sent for distillation, and winery waste water (used for cleaning in the course of pressing) is recycled and treated so as to avoid any risk of environmental pollution.