Riddling

in

 Riddling consists in drawing the yeast deposit that forms after bottle fermentation down towards the neck of the bottle.
The bottle is then rotated successively to left and right several times a day and is inclined from a horizontal to a vertical position "on its end".
In Champagne, riddling used to be done by hand, and this is still the case for our jeroboams and magnums of Brut de Nominée. Nowadays, it is more usually done using automatic machines, known as gyropalettes.

Images: 
You need flash player to visit this website.