In a large mixing bowl, whisk together flour, sugar, baking powder, salt, and zest of a lemon.
2 (250g) cups all-purpose flour, ¼ (50g) cup granulated white sugar, 2½ tsp baking powder, ½ tsp fine sea salt, 1½ tsp lemon zest
Using a cheese grater or a food processor with the grating attachment, grate your cold butter into bits.
½ (113g) cup unsalted butter
Add the butter to the dry ingredients, and coat all of the butter with the dry ingredients until the butter forms pea sized crumbles.
Add the honey, cold sourdough discard, buttermilk or milk, egg, and vanilla to the dough.
¼ (65g) cup sourdough discard, ¼ (60g) cup buttermilk, 1 large egg, 2 (30g) Tbsp honey, 1 tsp vanilla extract
Mix the dough with your hands or a pastry blender until the dough starts to ball together. At this point once the dough starts to comes together you're going to add the blueberries. You'll want to mix the dough gently after adding the berries to avoid them bursting and bleeding.
1½ (200g) cups fresh blueberries
Note about the blueberries: for the best results you should use fresh blueberries. If you need to substitute, you can swap for freeze-dried or dried blueberries evenly. If you choose to use frozen blueberries, I recommend using wild as they're smaller and release less moisture. Don't thaw them and coat them in 1-2 Tablespoons of flour and add them directly to the dough.
Gently work the dough until the dough comes together and no dry bits remain. The key to these scones turning out is making sure the flour is mixed in and absorbed, but you also don't want them overworked and tough.
You should see no floury bits left, and minimal cracks in your dough when it's done being mixed and the blueberries should be well distributed.