A quiet revolution of sorts is going on in the San Joaquin Valley, particularly on the rich alluvial soils of the Westside. Some winegrape growers are dealing with low concentrate prices by pulling out vines, but others are betting they will succeed with sheer volume. Well, there is only so much a poor vine can do, one might say; but hope may lie in some promising new super-producing varieties. The figure, 26 tons to the acre, may sound outrageous or like some delusional dream, but "not s...