By Lenn Thompson, Founder and Editor-in-Chief I had never heard of, let alone tasted, a wine made from the Rkatsiteli grape until I tasted a 2006 bottling from Dr. Konstantin Frank Vinifera Wine Cellars, on the western shore of Keuka Lake. I loved that wine and it's riesling-meets-gewruztraminer-meets-sauvignon blanc aromas and flavors, all wrapped up in great acidity and length. I still have a couple bottles in my cellar. I've heard that it ages beautifully, so we'll see. And so, it was with much excitement that I got to try the Dr. Konstantin Frank 2007 Rkatsiteli ($18). The nose is…