Google “GSM” and you’ll find no mention of wine on that first page of results. For a wine lover, GSM stands for the grapes Grenache (Greh-NAH-sh), Syrah (Seer-AH), and Mourvèdre (More-VED-rah) – three red beauties delicious on their own, but magical when blended together. Winemakers around the world love blends. Why? Because you can highlight…