When I was in Canada last month I had a chance to watch Viniserve’s mobile disgorging line in operation. Disgorging is a vital stage in the life of a sparkling wine. It’s the point when the dead yeast cells (from the secondary fermentation that creates the bubbles) are expelled. A process called riddling has localised them to a clump in the neck of the bottle, so they can be removed without losing too much wine. Then the bottle is topped up, and then it is corked.
In this video we see the process in action: the neck of the bottle is frozen, the crown cap is removed, the dead yeast cells are expelled, the wine is topped up, and the cork and wire (muzelet) are applied.
The advantage of a mobile line like this is that it is used all the time, well maintained, properly calibrated, and operated by experienced personnel. Of course, wineries can have their own lines, but unless they are sparkling specialists, it usually doesn’t make sense. Or they can hand disgorge, which is fun for the first 10 minutes, I suspect.