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Sliced sourdough discard blueberry loaf with lemon glaze and lemon zest

Sourdough Discard Blueberry Loaf with Lemon Glaze

A sourdough discard blueberry loaf with a tender, berry-marbled crumb and a tangy lemon glaze — sweet, simple and made with unfed starter straight from the fridge.
Prep Time 15 minutes
Cook Time 50 minutes
Cooling 45 minutes
Total Time 1 hour 50 minutes
Servings: 15 slices
Course: Dessert, Snack
Cuisine: Nordic

Ingredients
  

Batter
  • 240 g all-purpose flour 2 cups
  • 8 g baking powder 2 tsp
  • ½ tsp fine salt
  • 113 g butter ½ cup / 1 stick, melted and slightly cooled
  • 200 g granulated sugar 1 cup
  • 2 large eggs room temperature
  • 1 tsp vanilla sugar or vanilla extract
  • 170 g plain Greek yogurt ¾ cup, full fat
  • 120 g sourdough discard ½ cup, unfed, straight from the fridge
Berries
  • 400 g fresh blueberries 2¾ cups
  • 1 tbsp all-purpose flour for tossing the berries
Lemon glaze
  • 300 g powdered sugar 2½ cups
  • 1 lemon, juced about 3 tbsp / 45 ml
  • 1 lemon, zested the same lemon — zest it before you juice it

Equipment

  • 9x5-inch metal loaf pan This is a full pan of batter, so you want the larger size — a 9x5 (2 lb / 8-cup) metal pan. Chef-tested pick for US kitchens.
  • Digital kitchen scale With 400 g of berries in a single loaf, weighing the flour is what keeps the crumb from going heavy.
  • Silicone spatula Folds the blueberries in without crushing them — a wooden spoon will streak the batter purple.
  • Fine zester / rasp grater Fine zester / rasp grater
  • Wire cooling rack The loaf has to be completely cool before it's glazed, or the glaze soaks in and disappears.
  • Parchment paper A parchment sling lifts a berry-heavy loaf out in one piece.

Method
 

  1. 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.
  2. Whisk the flour, baking powder and salt together in a bowl and set aside.
  3. 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.
  4. 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.
  5. Toss the blueberries with 1 tbsp flour, then fold them in gently, holding back a small handful to scatter over the top.
  6. 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.
  7. Cool in the pan for 15 minutes, then lift the loaf out by the parchment and let it cool completely on a rack.
  8. 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.
That acidity is also why the crumb stays tender. Between the discard and the yogurt, this loaf is better on day two than it is on day one. Keep it covered at room temperature for up to three days.
Why so many berries? 400 g in one loaf is deliberate — it's what gives you the marbled crumb instead of a few berries scattered through plain cake. It also means a longer bake, so trust the skewer rather than the clock. Tossing the berries in flour keeps them suspended instead of sinking to the bottom.
Frozen blueberries work. Don't thaw them, and add 5 minutes to the bake time.
A note on the glaze. This is a generous, opaque white glaze — enough to cover the whole top and run down the sides, which is how it looks in the photo. Lemons vary a lot in juice, so add the juice gradually rather than all at once: too thin and it soaks in instead of setting. If you'd rather have a thin drizzle, make half.
A note on the pan. This makes a generous 9x5 loaf — about 8 cups of batter and berries. If your pan is smaller split the batter between two smaller loaf pans and bake for about 40 minutes instead. Two shallower loaves bake more evenly with this much fruit, and you get a second one to give away.