Chardonnay is the most-planted white grape on Long Island, covering around 30% of local vineyard land. That's a lot of chardonnay, relative to the white grape that I think holds the most potential for the region, sauvignon blanc, which covers far less than 5%.  That's also a lot of mediocre chardonnay. A lot of chardonnay that (usually) isn't going to do much more than fill the white wine columns on tasting room sheets. Don't get wrong, there are some outstanding, well-made Long Island chardonnays — made both with and without barrels — but Long Island is never going to be…