Adding the buttermilk is a crucial step that brings the dough together while also adding a subtle tang that enhances the overall flavor. Its acidity reacts with the baking powder, helping the scones rise and creating a tender, fluffy texture.
When mixing in the buttermilk, it’s important to pour it gradually and stir gently with a fork just until the dough starts to come together. You don’t want to overmix—keeping the dough slightly shaggy ensures the scones stay light and soft once baked.