So that's it.
I opened my very last bottle of Pontac last night, Hartenberg 1998 (Stellenbosch).
No more is available, those ancient diseased vines were pulled up after the 2000 vintage. The wine sold out long ago at the winery.
No one else anywhere makes a varietal Pontac, and it seems the variety itself will soon, after some 300 years growing in the Cape, vanish.

