The growing season in 2010 might have caused headaches for California winemakers, but you couldn't tell from many of the Zinfandels they produced. The 2010 vintage is not quite at the level of 2009, 2008 and 2007—among the best vintages in years—but it delivers a surprising number of flavorful and well-balanced wines. Yet consumers should still shop carefully, because there is no shortage of spotty wines. The growing season tested the mettle of every Zin producer in the state, though some regions were hit harder than others by nature's wrath. Stylistically, the wines are all over the map, even by Zinfandel standards, with some overripe versions and others very high in acidity. Wine Spectator's Tim Fish explains.