Each harvest is unique and different from the previous one, in terms of grape maturity, acidity and alcohol content. It's essential to choose the right moment to harvest.
Today, the network includes 602 control plots, on which, using a pre-established methodology, the average weight of bunches, their sugar content, total acidity, percentage of veraison (ripening) and grey rot are determined twice a week.
The results are transmitted electronically the same day. The Comité Champagne can then publish statistics for each plot and averages of variables (potential degree, acidity, etc.) by department for each grape variety.
The main technical managers, and in particular the regional correspondents of the Association Viticole Champenoise (AVC), are then informed of the results of the sampling. This enables them to specify their wishes concerning the opening date of harvesting in their commune at the harvest preparatory meeting.
Harvesting in Champagne remains entirely manual and traditional, as the constraints of respect for the grapes are the same as in the 18th century. Harvesting takes about 3 weeks. This is due to the very short optimum ripening time of the grapes. What's more, the different Champagne grape varieties ripen almost simultaneously.
There are around 120,000 grape-pickers, or 4 per hectare. Nearly 100,000 seasonal workers are housed and fed each year by winegrowers and wineries.
There are many different harvesting professions:
There's the picker, the basket carrier, the crate unloader, the manual truck loader, the dock worker, the transport vehicle driver, the forklift operator, the presser, the winery employee, the cook, etc...
Yields are regulated by the I.N.A.O., which sets the annual yield at 10,400 kg/ha. Each year, this basic yield may be reduced or increased by the I.N.A.O. depending on the quality and volume of the harvest.
However, quantities classified as appellation cannot exceed a maximum of 15,500 kg/ha. This level is due first and foremost to the high density of vine planting in Champagne: 8,000 vines per hectare. This density has a quality objective. It favors better ripening of the grapes, thus enhancing their quality.
In addition to this harvest yield, the pressing yield is limited to a maximum of 102 liters of juice for 160 kilos of fruit. This brings the final yield to 66 hectolitres per hectare.
The Champagne industry has decided to introduce a compulsory individual reserve. All growers are required to build up a reserve in years characterized by excellent quality harvests. These wines are stored in temperature-controlled vats to meet exceptional demand, such as at the turn of the millennium, or to compensate for a poor harvest, as was the case in 2012.