[Moderator's note: This post deals with Dave's Winemaker's Diary notes of January 11, 1999 and January 17, 1999.]
I can somewhat explain your pH difference in your Pinots (I think).
Our pHs are always higher the more whole clusters that we use - thus it
makes complete sense to me that the pH on the carbonic Pinot Noir was the
highest. In fact, one of the great controversies in Burgundy right
now is amongst winemakers who usually use a high percentage of stems in
their wine but, because of replanting with less acid-retentive clones, they are finding the wines have higher pHs and thus some are cutting back on the number stems in the fermentation.
The alcohol differences in the Pinot seem harder to explain. My guess would be that it is tied to yeast types. We get radically different conversion ratios depending on the yeasts we use.
Hope that helps a bit.