Another term for crown cork.Yeast is dispensed into it and it is then plugged before the bottle is stoppered with the usual crown cap....
Once the blend is completed the wine is put into bottles with a bit of sugar and yeast, the bottle is sealed with a crown cap and the fermentation that makes the bubbles commences.
I asked him if Bollinger would ever eschew corks for crown caps, to avoid the cork taint so pervasive in the wine industry.