When it comes to a wine’s sweetness, generally I gauge by alcohol. It’s the sugar in the grape juice that all those little yeasties turn into alcohol. Generally (there’s that word again), the lower the alcohol, the higher the grape sugar remaining in the wine (residual sugar), and the sweeter the wine. Rieslings, however, especially German Rieslings, are in a class by themselves when it comes to dry, off-dry or sweet. At 8.5 percent alcohol, with a balanced tension between the residual sugar and Riesling’s natural acidity, it can taste like biting into a fresh, juicy peach—one you have to finish over the sink. Then there’s this Pfeffingen, from Germany’s Pfalz region: the grapes come from an estate vineyard that dates back some 250 years. At 12.5 percent alcohol it’s dry, bone dry—no, stone dry. The fruit flavors, lime zest, apricot pit and a hint of pineapple, are sharpened to a pencil point. The soil, with its fossilized limestone and Roman ruins (they’ve actually unearthed an ancient bath house on the property), contribute a minerality that the wine’s lack of sweetness allows to come through. Gave me the impression that the Pfeffingen was poured over clean, runoff river stones. Mmmmm. I had it with chips and salsa and it was great, but it should be even better with fish.