In glass measuring cup or a bowl, stir lemon juice into milk; set aside. In a large bowl, combine 2-3/4 cups (675 mL) flour, sugar, baking powder, baking soda and salt. Using pastry blender or two knives, cut in butter until mixture is crumbly. Pour in milk mixture; stir with a fork until a soft, sticky dough forms.
Turn out onto a floured surface and, with floured hands, gently knead in cranberries, trying to not crush them and adding more flour to prevent sticking as necessary, until dough comes together and cranberries are dispersed. Pat out to a 9-inch (23 cm) circle; cut into 12 wedges. Place on prepared baking sheet, at least 1-inch (2.5 cm) apart.
Brush tops of scones with milk and sprinkle with sugar. Bake for 15 to 20 min, switching pans on racks halfway if using 2 sheets, or until puffed and golden. Let cool for at least 10 min before serving.