No, if the DOC / DOCG stipulations do not allow a variety to be used. And I’m not sure, but Verduno Pelaverga might be the only appellation that allows varietal Pelavergas.
Furthermore, Pelavergas are grown in many parts of Piedmont, but they are normally blended with other varieties and IIRC, Verduno Pelaverga aka. Pelaverga Piccola is a distinct variety not grown much or at all outside Verduno.
But a great thread here! Basically all my favorite Piedmontese grape varieties mentioned in the first handful of posts.
Some of my own observations:
Timorasso is definitely some of the greatest white varieties grown in Italy, probably even in Europe. The best examples are ridiculously impressive and remarkably fresh and structured for their size. They can also easily develop for a few decades, so drinking them with within the first few years is simply sacrilegious. The aforementioned Walter Massa is a producer in its own class, but the higher-tier bottlings of Claudio Mariotto can be also very impressive.
If I’ve understood correctly, Ruchè (or Ruché) and Freisa used to be made into this somewhat sweet and slightly frizzante style, but nowadays, after the modern vinification methods have reached even the bumpkins of Piedmonte, they’ve learned to make terrific dry still red out of these varieties and they can be mighty delicious. Ruchè seems to do anything from a light and playful wine to a taut and tannic one, but they always seem to carry this very floral, Gewürztraminer-ish rosewater aroma. Freisa is probably my favorite Piedmontese red variety with Nebbiolo and Verduno Pelaverga.
Brachetto seems to be the only variety which is still predominantly made into this sweet and fizzy style. I’ve tasted some still and dry examples, but they have been very unimpressive: they smell just lovely, but flavor-wise they seem to be quite hollow, flat and dull with very modest acidity. This variety really seems to call for some residual sugar to flesh out its body.
Arneis is a real chameleon. The wines range from light, crisp and racy that show almost Muscadet-like neutrality to the very textural, waxy and weighty style that might even see some skin contact. Nascetta seems to be a very similar variety, but made on the Barolo side of the Tanaro river. The best Nascettas are among the greatest whites of Piedmont, along with Timorassos.
I’ve yet to taste an interesting Cortese or Favorita. They seem to produce just neutral, dull and boring whites. Also, I’ve never tasted a wine made of Avarengo, but I’m definitely interested in getting my my hands on some.
Somebody also mentioned Fumin. I have probably never tasted a bad Fumin (although I can imagine it’s not a variety that is everyone’s cup of tea), but I think the wines and varieties of Aosta Valley call for a thread on their own, or this discussion will soon spiral out of control!