Every year the Champagne region of France announces the start dates for the harvest. This start dates vary by each village and grape varietal, ensuring that every plot is picked at the optimal ripeness. But then How is the date of harvesting decided?
The bunches of grapes reach optimum ripeness at different times depending on the variety of grape and the place where it grows. So it is important to monitor the ripening process by observing the grapes in each growth – a responsibility that falls to the Réseau Matu (ripening observation network).
Consisting of volunteer professionals, the Réseau Matu monitors ripening in 600 vineyard plots that represent the Champagne vineyard as a whole. Twice a week, clusters of grapes are picked, weighed and then pressed.

The juice is then immediately analysed to measure total sugar content and total acidity and using these data to assess the grape samples for ripeness.

Based on the location of the vineyard, local representatives put forward a date that looks right for harvesting each of the varieties in their particular growth. The Association Viticole Champenoise (AVC) then collates this information and suggests a provisional harvest calendar for each vineyard. On the basis of these proposals, the exact dates for the start of harvest, village by village, are fixed each year by prefectoral decree. Any deviation from these dates and the entire harvest will forfeit its right to Champagne AOC status.
Harvesting earlier than the stated date is only possible with a dispensation from the Institut National des Appellations d’Origine (INAO).
Further, each year based on professional advice the INAO sets the maximum authorised yield per hectare that will be entitled to AOC status. Any surplus, known as DPLC (dépassement du plafond rendement autorisé) must go for distillation – it cannot be used to make wine of any description whatsoever.
Source – https://bit.ly/30Bj66A