The pressing of the grapes is difficult, since the juice of what is to be a white wine must not be tainted by the skin of the mainly black grapes used. The traditional champagne press was a vertical basket press, holding 4,000 kg/8,800 lb of grapes, a quantity known as a marc and a standard unit of measurement in the region. These presses are also called Coquard presses after the name of the manufacturer. A number of other types of press have since been introduced and the CIVC allows both hydraulic and pneumatic horizontal presses.
