Preheat the oven to 350 F
Grease a 9 x 5" loaf pan with coconut oil or butter, or line it with unbleached parchment paper.
Mill your flour (if using fresh)
In a large bowl, whisk together all of the dry ingredients: flour, baking powder, baking soda, salt, and lemon zest.
In another bowl, combine all of the wet ingredients: melted coconut oil, sourdough discard, honey, eggs, milk, and lemon juice. Mix until well combined.
Now add the wet ingredients to the dry ingredients, but don't overmix. Mix everything together until just combined.
Gently fold the blueberries into the batter.
Pour the blueberry lemon loaf batter into the prepared loaf pan
Bake for 55-60 minutes or until a toothpick inserted into the middle of the loaf comes out mostly clean.
Let the bread cool in the pan for about 10 minutes, and then gently remove it onto a wire cooling rack to cool the rest of the way.
While the bread is cooling, prepare the lemon glaze by combining the lemon juice and powdered sugar together.
Pour the glaze evenly over the sweet bread. Slice, and enjoy!