originally posted by Ken Schramm:
OK, I’m going to geek a little heavily here.
I have experienced this situation in Huets in various sweetness levels from different vintages, and it has occurred in random bottles, meaning that I have pulled subsequent bottles of the same wine and not experienced the same compromised state.
I have been suspicious of the causes of bottle variation, and I am willing to posit one potential source.
We use a GAI bottle rinser, a GAI 1308 filler/corker, and a GAI encapsulator/labeler. The filler/corker has a deaerator, which replaces the room air with nitrogen before filling, along with a leveler/injector, which adjusts the fill level to meet the cork size, and also re-fills the head space with nitrogen right before cork insertion. You can see video of this process
here (this video was shot before the bottle rinser was added to the line).
The bottles between the deaerator and the filler heads, between the filler carousel and the injector, and between the injector head and the corker are exposed to room air. When the line is running at speed, that exposure is very short. During any bottling run, however, there will be occasional line stoppages, sometimes to clear a jam, and when necessary, to change label rolls. During those stoppages, those bottles can sit in place, with their aperture exposed to room air. Oxygen being heavier than nitrogen, there is the opportunity for gas exchange. If you are dealing with a mechanical fault, that exposure can be protracted.
This would not account for this happening on a large scale, but it could account for more than a few bottles per packaging session, and potentially consecutive bottles in a given case. We have changed our SOP to fully clear the filler/corker and set the corked bottles aside during all stoppages anywhere else on the line, to minimize this risk.