If the boule is the loaf you make for guests, this is the loaf you make for yourself. It's the bread that turns up in lunchboxes, the bread you toast at six in the morning, the bread that holds together when you build a real sandwich.
Most published "sourdough sandwich loaves" are essentially yeasted bread with a token spoonful of starter for marketing. This one is real sourdough — it ferments overnight in the fridge for flavour, and the milk and honey in the dough keep the crumb soft enough that nobody at school will trade it away.
What you'll need
For one loaf
- 100 g (½ cup) active sourdough starter, ripe and bubbly
- 200 g (¾ cup + 2 tbsp) lukewarm whole milk
- 150 g (⅔ cup) lukewarm water
- 30 g (1½ tbsp) honey or maple syrup
- 30 g (2 tbsp) softened unsalted butter
- 500 g (4 cups) bread flour or strong all-purpose flour
- 10 g (1¾ tsp) fine sea salt
- Soft butter, for greasing the pan
Flour notes
Canadian bakers using Robin Hood, Five Roses, No Name, or PC AP (≈13% protein) — use the AP straight. The high protein is exactly what an enriched dough wants.
US bakers using King Arthur, Gold Medal, Bob's Red Mill AP (10.5–11.5% protein) — use bread flour for this recipe, not AP. The enrichment from milk and butter shortens the gluten; you need the structural support of a higher-protein flour.
Half whole-wheat option: swap 200 g of the bread flour for whole-wheat flour and add 25 g extra milk. The crumb stays surprisingly tender.
The method
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Mix · 5 minutes hands-on
In a large bowl, whisk the starter into the milk, water, and honey until smooth. Add the softened butter and whisk again — it doesn't need to fully emulsify, small streaks of butter are fine. Add the flour and salt and mix with a spatula or wet hand until no dry streaks remain. The dough will be sticky and soft. Cover and rest 30 minutes.
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Stretch and folds · 2 hours
Over the next 2 hours, do four sets of stretch-and-folds, 30 minutes apart. Wet your hand each time. The dough will be tackier than a lean sourdough — that's the milk and fat. By the fourth set it should feel smooth and supple, holding its shape when you pull it up. Cover.
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Bulk fermentation · 3 to 5 more hours
Leave the dough to finish bulking after the last fold. It's ready when it has grown by 50 to 70 percent and the surface is smooth and softly domed. Enriched doughs ferment a little slower than lean ones because the fat coats the gluten — give it time. In a 22°C kitchen, expect 4 hours total. In a 19°C kitchen, expect 6 to 7.
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Shape · 5 minutes
Lightly grease a 9×5 inch (23×13 cm) loaf pan. Tip the dough onto a lightly floured counter. Pat it into a rectangle roughly the length of the loaf pan. Roll it up tightly from the short end like you're rolling a yoga mat, pinching the seam closed as you go. Place seam-down in the greased pan, tucking the ends under so the loaf sits evenly.
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Cold proof · 12 to 18 hours
Cover the pan with a shower cap, plastic wrap, or a fitted lid and slide it into the fridge. The long cold proof develops flavour and gives this loaf its quietly tangy, complex character.
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Final proof · 1 to 2 hours at room temperature
Take the pan out of the fridge. Let it warm up at room temperature, uncovered for the last 30 minutes. The dough is ready to bake when it has risen to about 1 cm above the rim of the pan and feels gently springy to a fingertip — the indent should slowly fill in.
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Bake · 40 to 45 minutes
Preheat the oven to 200°C / 400°F about 30 minutes before you plan to bake. Brush the top of the loaf gently with milk for a deep golden crust (a beaten egg works too if you want gloss). Bake for 40 to 45 minutes, tenting loosely with foil at the 25-minute mark if the top is browning faster than the loaf is baking through. Internal temperature should reach 95°C / 203°F.
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Cool fully before slicing · at least 1 hour
Tip the loaf out of the pan immediately — leaving it in traps steam and softens the crust. Cool on a rack for at least an hour. Slice with a serrated knife. The first slice is the cook's slice. House rule.
Climate notes
Cold winter kitchens (anything under 20°C / 68°F) — bulk fermentation on this enriched dough can stretch to 7 or 8 hours. Use a turned-off oven with the light on as a proofing chamber. Add 10 g extra milk to the recipe to keep the dough from feeling tight.
Humid summer kitchens — reduce milk by 10 g. Bulk in the fridge instead of on the counter if your kitchen is above 26°C, or the dough will overferment.
Pullman variation: if you have a Pullman pan with a sliding lid, slide the lid on for the full bake to get a flat-topped, perfectly square loaf. Add 5 minutes to the bake time.
Variations
- Cinnamon swirl. Roll out the shaped dough into a rectangle, brush with melted butter, and sprinkle with 3 tablespoons of brown sugar mixed with 1 tablespoon of cinnamon before rolling and panning. School lunch hero.
- Seeded sandwich. Add 60 g of mixed seeds (sunflower, sesame, flax) to the dough at the mix stage. Roll the shaped loaf in additional seeds before placing in the pan.
- Multigrain. Replace 100 g of bread flour with a soaker — 60 g rolled oats and 40 g cracked rye, soaked in 100 g water overnight. Add the soaker at the mix stage.
- Vegan. Replace milk with oat milk, butter with refined coconut oil, honey with maple syrup. Crumb stays soft.
Storage
This loaf is happiest stored cut-side-down on a board for the first day, then in a breathable linen bag for the rest of the week. Store-bought sandwich bread defaults to plastic because it has to survive transit and shelf life. A homemade loaf doesn't — it just needs to breathe.
For us, that's the beeswax linen bread bag we make. Any clean tea towel or unbleached cotton bag is the principle if you don't have one yet.
For longer storage: slice the cooled loaf, layer the slices in a freezer bag with parchment between every two or three slices, and freeze. Toast slices straight from frozen — they barely lose anything.
Common questions
Is sourdough sandwich bread softer than regular sourdough?
Much softer. Milk, butter, and honey in the dough soften the crumb dramatically — the texture lands somewhere between yeasted sandwich bread and a lean sourdough. You get the soft slice, the long-fermented digestibility, and a quietly complex flavour that store-bought sandwich bread can't match.
Can I make this dairy-free?
Yes — swap whole milk for the same weight of unsweetened oat or soy milk, and butter for the same weight of refined coconut oil or a plant-based butter. The crumb stays tender. Almond milk works less well; the lower protein leaves the crumb a touch dry.
What size loaf pan should I use?
A standard 9×5 inch (23×13 cm) pan in metal or enameled cast iron. A Pullman pan with a sliding lid will give you the perfectly square slice you'd recognize from a bakery — bake 5 minutes longer with the lid on.
How do I keep sandwich bread fresh longer?
Cool the loaf fully — never wrap warm bread, ever. Then store cut-side-down on a board, or in a breathable linen bread bag. Properly stored, this loaf holds for 4 to 5 days. Beyond that, slice and freeze; toast slices straight from frozen.
Why does the cold proof matter?
The cold proof is what makes this real sourdough rather than just sourdough-flavoured. The slow fermentation in the fridge develops complex flavour compounds and pre-digests the gluten, which is part of why long-fermented bread is easier to digest than fast-yeasted commercial loaves. Skipping the cold proof gives you bread that tastes flatter and feels heavier.