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Walnut sourdough bread sliced open on a wooden board, showing walnuts through the open crumb

Walnut Sourdough Bread

A hearty whole grain walnut sourdough with a deep, nutty flavor — the walnuts blanched first to take the bitterness out.
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Prep Time 45 minutes
Cook Time 35 minutes
Fermenting & proofing 20 hours
Total Time 21 hours 20 minutes
Servings: 1 loaf
Course: Bread, Breakfast
Cuisine: Nordic, Scandinavian
Ingredients Equipment Method Notes

Ingredients
  

Walnuts
  • 200 g walnut halves about 2 cups — blanched, see step 1
Starter
  • 140 g active sourdough starter about ⅔ cup — bubbly, doubled and at its peak
Dough
  • 400 g water about 1⅔ cups, lukewarm
  • 300 g bread flour about 2½ cups — or sifted landhvete if you're in Scandinavia
  • 150 g whole wheat flour about 1¼ cups — or fine wholemeal landhvete
  • 100 g coarse stoneground whole wheat flour a scant 1 cup — or coarse wholemeal landhvete
  • 15 g fine sea salt about 2½ tsp
For the basket
  • rice flour a few tablespoons, for dusting — resists sticking far better than wheat flour

Equipment

  • Digital kitchen scale This dough runs at 73% hydration — weight, not cups.
  • Small saucepan For blanching the walnuts.
  • Bench scraper Folding 200 g of walnuts into a wet dough is where hands alone start tearing it.
  • Banneton proofing basket Holds the dough's shape through the overnight rise. A heavy nut dough sticks more than a plain one, so dust it well.
  • Linen proofing cloth Lines the basket; rice flour plus linen is the combination that releases cleanly with inclusions in the dough.
  • Bread lame A clean, deep score. Walnut halves near the surface will catch a dull blade.
  • Perforated baking tray Lets heat reach the base so the bottom crust sets properly. Preheat it with the oven.
  • Metal roasting tray Your steam source on the rack below. Metal only, never glass.
  • Instant-read thermometer 205–210°F (96–99°C) in the center. Nut breads look done before they are.
  • Wire cooling rack The loaf needs air underneath while the crumb sets.

Method
 

Before you start
  1. Blanch the walnuts. Bring a small pot of water to a boil, add the walnuts and boil for 1–2 minutes. Drain, rinse under cold water and drain well. Spread them out on a towel while you mix the dough. One blanch is enough, and they don't need to be bone dry — damp is fine.
Day 1
  1. Feed your starter the morning you bake (or the night before) so it's lively when you mix — it should have roughly doubled and look domed and bubbly. A spoonful floating in water is a good extra sign, but a whole grain starter can sink even when it's ready, so trust the rise first.
  2. Mix the dough. In a large bowl, whisk the starter into the lukewarm water to loosen it. Add all three flours and mix by hand until no dry flour remains — you'll have a shaggy, sticky dough. Hold the salt back for now. Cover and rest 1 hour at room temperature.
  3. Add the salt. Sprinkle it over the dough and work it in thoroughly, squeezing and folding until fully incorporated. The dough will tighten up slightly.
  4. Stretch and fold — every 30 minutes, at least 4 times — adding the walnuts on the second set. With a wet hand, grab one side of the dough, stretch it up, and fold it over the center; turn the bowl a quarter turn and repeat around the whole dough (four pulls = one set). On the second set, flatten the dough, scatter the walnuts over the surface and fold them in; the remaining sets will distribute them evenly. Our Stretch & Fold Timer keeps track of the sets for you.
  5. Bulk ferment until risen. After the folds, cover and let it rise at room temperature until it's grown by about 30–50%, looks domed and jiggly, and shows bubbles on top and along the sides. Depending on your kitchen this is roughly 4–6 hours total from mixing — the walnuts can slow it down a little, so give it the time it needs. Watch the dough, not the clock; our guide to bulk fermentation shows you what to look for.
  6. Preshape and shape. Tip the dough onto a lightly floured surface and gently round it into a loose ball. Leave it uncovered for 20–30 minutes so the gluten relaxes. Then fold it into a taut round, pulling it toward you against the counter a few times to build surface tension — more on that in how to shape sourdough. Press any walnut that pokes out back into the dough as you go.
  7. Into the banneton. Line your proofing basket with a cloth and dust it generously with rice flour, then set the dough in seam-side up.
  8. Cold retard overnight. Cover and refrigerate 12–16 hours. The slow, cold rise builds flavor and firms the dough so it's easier to score and springs higher in the oven.
Day 2
  1. Preheat, hot. About 45–60 minutes before baking, heat the oven as hot as it goes — around 480°F (250°C) — with your perforated baking tray on the middle rack and an empty metal roasting tray on the rack below. Both metal, never glass — glass can shatter when the water hits it.
  2. Turn out and score. Turn the cold dough out onto a sheet of parchment, seam-side down. Score it once, decisively, about ½ inch (1 cm) deep — see how to score sourdough.
  3. Bake with steam. Slide the loaf, still on its parchment, onto the hot baking tray in one quick movement. Immediately pour about 1 cup of just-boiled water into the roasting tray below and shut the door fast. Bake at 480°F (250°C) for 20 minutes.
  4. Finish in dry heat. Take the roasting tray out, drop the oven to 400°F (200°C), and bake another 15 minutes until the crust is deep brown and the center reads 205–210°F (96–99°C). Our guide to sourdough baking temperature explains the heat and steam in detail.
  5. Cool completely. Cool on a wire rack for at least 2 hours before slicing. A nut loaf holds moisture longer than a plain one — cutting early gives you a gummy crumb.

Notes

Chef's tip — blanch the walnuts. The bitterness sits in the papery brown skin, and a two-minute boil pulls a good part of it out — you'll see the water turn brown. Skip it and the bitterness carries into the crumb and sharpens as the loaf ferments.
  • Damp walnuts are fine. Straight from the towel into the dough — no toasting, no drying. Just don't tip the draining water in with them.
  • Sticky is right. The whole grain flours drink up water, so this sits around 73% hydration. It'll feel tacky — that's exactly what you want.
  • Nuts slow things down. Walnut tannins are mildly hostile to gluten and to your starter, so this dough can ferment a touch slower and feel a little slacker than the plain loaf. Judge the dough, not the clock.
  • A lavender tint is normal. Walnut tannins can turn the crumb around the nuts faintly purple-grey. Blanching reduces it; it doesn't affect the flavor.
  • Weigh, don't scoop. A digital scale is the single biggest upgrade for consistent sourdough; the cup measures above are approximate.