It looks like what they are making the vinager from is the lees of the wine. If I remember correctly, you have Termium, so don't know how much more help I can be, but Termium does have the following: English:Winemaking

dégorgement s CORRECT

DEF - The process for removing the deposit formed during the secondary fermentation. s
CONT - When the crown cap, or cork, is removed and the yeast deposit is ejected, the process is called disgorging, or "dégorgement". The bottle is quickly turned to an upright position. s

and here is an entry from LGDT: Domaine(s)
alimentation
boisson alcoolique

disgorging (a)
In the production of sparkling wines and meads, the removal of the residue of dead yeast cells which have accumulated on the side of the bottle and below the cork. (c)

dégorgement n m (b)
En champagnisation, l'opération qui consiste à enlever le dépôt de levures mortes qui s'est formé sur la paroi de la bouteille et sous le bouchon. (c)

[1986]