Danish / Scandinavian
Nordic Seeded Dark Rye & Spelt Sourdough Rugbrød
Copenhagen’s iconic dense, malty whole-grain longevity bread (Rugbrød): no kneading or folding required—cracked rye berries, flaxseeds, sunflower seeds, and pumpkin seeds are soaked overnight alongside a whole-rye sourdough ferment, baked in a pullman tin, and cured in linen for razor-thin open-faced smørrebrød slices.
The good part
Fermentation Science & Baker’s Notes
Rye flour contains high amylase activity that can liquefy starch into a sticky paste if not acidified. A 30%+ sourdough starter inoculation drops dough pH below 4.6, inhibiting excess alpha-amylase and setting the pentosan sugar gel into clean, sliceable Danish smørrebrød squares. For deeper fermentation diagnostics, Desired Dough Temperature math, and starter ratios, consult our Ancient Grain & 100% Dark Rye Sourdough Mechanics and the master Vegan Sourdough & Wild Fermentation Pillar Hub.
Storage, Freezing & Refreshing
Store crusty artisan sourdough loaves cut-side down on a wooden board or inside a linen bread bag at room temperature for up to 3 days (avoid sealed plastic bags, which trap moisture and soften the blistered crust). For longer storage, slice the cooled loaf completely, place parchment squares between slices, and freeze in an airtight freezer bag for up to 3 months; toast straight from frozen or refresh whole loaves in a 375°F oven for 8 minutes.
Nutrition, Digestibility & Swaps
A nutritional powerhouse delivering 9g of fiber, 8g of plant protein, and rich lignans and omega-3s in every two-slice serving. Want to adapt another family bakery recipe to 100% plant-based sourdough? Open our interactive Vegan Baking Converter.
Gather
Ingredients
- For Overnight Seed & Grain Soaker: 100g (2/3 cup) cracked rye berries or steel-cut oats + 70g (1/2 cup) raw sunflower seeds + 70g (1/2 cup) raw pumpkin seeds (pepitas) + 50g (1/3 cup) whole brown or golden flaxseeds + 300g (1 1/4 cups) boiling water + 14g (2 1/2 tsp) fine sea salt
- For Dough: 350g (3 cups) whole dark rye flour (pumpernickel meal)
- 100g (3/4 cup) whole spelt or whole wheat flour
- 150g (2/3 cup) active 100%-hydration rye or wheat sourdough starter
- 220g (scant 1 cup) lukewarm water or dark vegan malt beer
- 25g (1 tbsp + 1 tsp) dark barley malt syrup or blackstrap molasses (gives authentic Danish mahogany color)
- 2 tbsp rolled oats and extra seeds, for coating the greased loaf tin
Make
Method
- 01Steep the Seed & Cracked-Grain Soaker (Overnight or 2 Hours): Combine the cracked rye/steel-cut oats, sunflower seeds, pumpkin seeds, flaxseeds, and 14g sea salt in a heatproof bowl. Pour 300g boiling water over top, cover, and let steep for at least 2 hours (or overnight) until all water is absorbed and seeds are plump.
- 02Mix Clay-Like Rye Batter (No Kneading): In a large bowl, whisk the 150g active sourdough starter, 220g warm water (or dark vegan beer), and 25g barley malt syrup/molasses. Add the 350g dark rye flour, 100g whole spelt flour, and the cooled seed soaker; stir vigorously with a heavy wooden spoon (or stand mixer paddle for 3 minutes) until a thick, heavy, clay-like batter forms.
- 03Pack Into Seed-Lined Loaf Tin: Grease a 9x5-inch loaf pan (or 9x4-inch pullman pan) generously with vegan butter or oil and coat the interior walls with rolled oats and sesame/sunflower seeds. Spoon the dense rye dough into the pan, smoothing the top flat with a wet spatula.
- 04Single Pan Rise Until Dock Holes Close (4 to 6 Hours): Poke a row of 1-inch-deep holes down the center with a wet skewer. Cover and ferment at 76°F–78°F for 4 to 6 hours until the dough rises by 35% to 40% (reaching 1/2 inch below the pan rim) and tiny fermentation cracks appear on the surface.
- 05Slow Steam Bake & 24-Hour Linen Cure: Mist the top with water, cover pan loosely with foil for the first 20 minutes, and bake at 375°F (190°C) for 65 to 75 minutes total until internal temperature reaches 208°F (98°C). Unmold immediately, wrap in a clean damp linen towel, and let cure at room temperature for 12 to 24 hours before slicing thin with a serrated knife.
Keep cooking
Swaps, storage, and useful next steps.
A nutritional powerhouse delivering 9g of fiber, 8g of plant protein, and rich lignans and omega-3s in every two-slice serving.