This French term refers to the various grape varietals planted on a particular estate. It's often used when speaking of properties in Bordeaux, as in "The encepagement for Haut Brion is 55% Cabernet Sauvignon, 22% Cabernet Franc, and 23% Merlot." This doesn't mean that the wine produced at the estate is necessarily in direct proportion to its encepagement; the exact conditions of each grape varietal—rather than the percentage planted—determine the proportion of the varietals used in the final blend.