It seems that just about everyone interested in Long Island wine knows Castello di Borghese, located on Route 48 in Cutchogue. You see, before the property was bought by Marco Borghese (an Italian prince) it was Hargrave Vineyard, where Alex and Louisa Hargrave founded the Long Island wine world back in 1973. If you're visiting Long Island wine country, you really should stop by Borghese to get a taste of that history. Focus on the pinot noir and cabernet franc when you're there. This Castello di Borghese 2007 Sauvignon Blanc Estate ($20) is a pale straw-yellow in the glass and…