Schonborn's 2007 Hattenheimer Pfaffenberg Riesling Beerenauslese - like its Marcobrunn counterpart, representing the berries culled from the eventual T.B.A. over an extended period - harbors a frightening 14 grams acid against 287 grams of residual sugar. Here caramel verging on burnt sugar and pure, honeyed secretion of botrytis cohabitate uneasily and discordantly with fresh lemon. This is viscous but certainly not heavy. it's also not texturally at all alluring, for now at least and for how many more years, or perhaps decades?. Low notes of toasted nuts and dark caramel and detached citrus are what linger longest, like a sustained piccolo-double bass duet. For those wealthy and brave enough this should be interesting stuff to follow. I have to admit that my teeth were on edge a bit in anticipation after tasting Schonborn's two B.A.s, and realizing that there was a corresponding pair of T.B.A.s. Peter Barth took over cellar duties in 2001, and direction of the entire, fabled Schonborn estate in 2006. I had not visited in all that time - only heard rumors of a revival (tales of a sort that are too often false alarms when it comes to large, underperforming, noble Rheingau estates) - so I am happy to report that the renaissance of Schloss Schonborn is for real. Ten years ago, I found Schonborn's dry wines too austere and their sweet wines exaggeratedly so. Examples of these extremes have not been eliminated, but there are plenty of gorgeous and without doubt age-worthy wines that steer a steady stylistic course. Although - like most large German estates - Schonborn has pruned the number of single-vineyard wines and styles on offer when compared with the enormous annual line-ups that prevailed until a decade ago, this has been done with sensitivity to synergistic blends, and allowing plenty of room for each of the domaine's most celebrated vineyards - in particular their monopole Hattenheimer Pfaffenberg with 12 bottlings this vintage! and Erbacher Marcobrunn - to show-off. Various importers, including Dee Vine Wines San Francisco, CA; tel. (877) 389-9463, Slocum & Sons, North Haven, CT; tel. 203-239-8000, Frederick Wildman & Sons, New York, NY; tel. (212) 355-0700