GSM The valley of the Rhône is the origin of the GSM grape varietals. Grenache, the base variety, brings fruity flavours, warmth, and body. In its seductive, lustrous red depths, the Grenache grape conceals a heady fullness and flavours of blackcurrant and rich spices. Syrah, black, peppery, well-structured, and Mourvèdre, full-bodied and well-structured give the wine their spicy aromas, and a colour and structure suitable for ageing.