Ingredients
Equipment
Method
- Heat the oven to 350°F / 180°C. Line a 9x5-inch loaf pan (8-cup / 2-litre capacity) with parchment, leaving an overhang on the long sides.
- Whisk the flour, baking powder and salt together in a bowl and set aside.
- In a large bowl, whisk the melted butter and sugar until smooth. Add the eggs one at a time, then the vanilla, yogurt and sourdough discard. Whisk until the batter is even and glossy.
- Fold in the dry ingredients with a spatula, stopping as soon as no dry flour is left. The batter should be thick and a little lumpy — don't beat it smooth.
- Toss the blueberries with 1 tbsp flour, then fold them in gently, holding back a small handful to scatter over the top.
- Scrape the batter into the pan, level the surface and scatter the reserved berries on top. Bake for 50–60 minutes, until a skewer in the centre comes out clean. If the top colours before the middle is set, tent it loosely with foil.
- Cool in the pan for 15 minutes, then lift the loaf out by the parchment and let it cool completely on a rack.
- Zest the lemon first and set the zest aside, then juice it. Whisk the powdered sugar with the lemon juice a spoonful at a time until you have a thick, slow-pouring glaze — it should coat the whisk and fall off in a ribbon, not run like water. Pour it over the cooled loaf, let it spill down the sides, and scatter the zest over the top while it's still wet.
Notes
Chef's tip — use the discard cold and unfed. This is one of the few sourdough bakes with no guesswork: the baking powder does all the lifting, so the discard is there purely for flavour and acidity. Straight from the fridge is exactly what you want — no feeding, no waiting for it to peak, no wondering if it's active enough.
