Long Island merlot is often — and consistently — delicious. But when Long Island cabernet franc is done well — which is almost always the case at Roanoke Vineyards — it is much more distinctive and compelling. At it’s best, Long Island cabernet franc combines forward, ripe fruit with savory notes — often herbs but sometimes mushrooms or leaf tobacco — and restrained oak that frames rather than overwhelms the grape’s varietal character. Usually there is a freshness too, which makes it one of my go-to wines for the dinner table. Of the 2010 cabernet francs I’ve tasted, Roanoke Vineyards 2010 Cabernet France ($34) best exemplifies my personal local…