I wonder regarding the closure variants and their use from the Champagne houses.
Especially the question which houses still use single-piece corks and for which bottles; Krug comes to mind…agglomerated cork for the regular cuvees vs. real cork for others like CdM, CdA? DP Oenoteque?
And then there is DIAM, but my question regards the solid ones - still used?
I used to work in cork, and I’ve seen single piece sparkling done only once. I believe it was Mt. Eden winery making a tiny-volume sparkling cuvee for an anniversary celebration, and they needed roughly a thousand corks. Portugal chamfered large formats for the project.
The cost was 10-15x the price of a grade A champagne cork. I do remember they were happy with the result.
We did small runs for some beers for Bear Republic as well, but they used standard-sized wine corks.
Edit: It was Kathryn Kennedy, not Mt. Eden. I knew it was SCM at least.