After the long resting period (maturation on the lees), the wine must be returned to its limpidity by eliminating the deposit formed during the sparkling process.
Riddling is designed to collect sediment (yeast and riddling additives) in the neck of the bottle, so that it can be removed during the disgorging process.
To do this, the bottles must be gradually moved from the supine position to the " on point " (upside down) position, in order to bring the deposit into the bottle neck.
This operation, known as "riddling", consists of turning the bottle successively to the right and left, then raising it to bring the deposit in the neck into contact with the cap.
The operation is still sometimes carried out manually, on wooden desks. A professional "remueur" can handle around 40,000 bottles a day. It involves turning the bottle 1/8 or 1/4 turn, left or right, from a chalk line drawn on the base, while gradually straightening it from horizontal to vertical.
These successive rockings, reproduced for centuries by cavistes-remueurs, allow the bulk of the deposit to pick up the smallest particles, resulting in a perfectly limpid wine.
A bottle is stirred by hand an average of 25 times over a period of one and a half months.
Today, riddling is mostly mechanized, with processes that can riddle metal crates containing 500 bottles. A " gyropalette ", working 24 hours a day, 7 days a week, reduces the riddling time from around 6 weeks to 1 week, without affecting the quality of the wine.
Before being sent for disgorging, the bottles are stored " en masse " (in stacks, upside down).