Bilberry is rather sour when eaten raw, but it becomes sweeter when cooked and maybe with a little sugar. Sauce made with lingonberries The most common recipe is the well-known Nordic lingonberry sauce, which pairs well with poultry and pork. You may also add blueberries to duck breasts to make them more flavorful. How to make a sweet version of lingonberries Its acidic flavor precludes it from being eaten raw as is; nevertheless, it may be processed into delightful jams, eaten dry in cakes and cakes, or even juiced.