Mulled wine is wine that has been heated with herbs, spices and citrus fruits, and sometimes sugar. The exact amount of calories in a glass of mulled wine varies depending on the recipe.
Using one 25-fl.-oz. or 750 ml bottle of a dry red wine, and heating it with added water, sugar, spices and fresh citrus peel, the resulting mulled wine provides around 840 calories. On a per-serving basis, that recipe translates to around 100 calories per half cup.
Cooking alcoholic drinks reduces the alcohol and calorie content; however, because mulled wine is usually simmered rather than boiled, around 35 percent of the alcohol is retained. The exact percentage depends on how long you cook it.
With any drink that contains alcohol, the body burns the calories derived from the alcohol before burning calories from fat, carb or protein sources. Therefore, drinking alcoholic drinks can interfere with the fat-burning process.