Rúgbrauð is Iceland's dense, dark, lightly sweet rye bread. It is closer to a moist, sliceable cake than a crusty loaf: the dough is a thick batter that needs no yeast, no kneading and no proving, and it gets its deep colour and caramel-like flavour from hours of gentle heat.
Traditionally it was baked in pots buried in hot, geothermally heated ground, where it cooked slowly for up to a day; bread made this way is called hverabrauð, "hot-spring bread". At home, the same result comes from a very low oven and a tightly covered tin. This recipe bakes at 100°C (210°F) for many hours.
Makes 1 large or 2 small loaves · Hands-on 15 minutes · Bake 7–12 hours
Ingredients
- 3 cups (about 340 g) dark rye flour
- 1½ cups (about 185 g) whole-wheat or plain (all-purpose) flour
- 2 teaspoons baking soda (bicarbonate of soda)
- 1 teaspoon fine salt
- 1 cup (about 340 g) golden syrup, or half honey and half molasses (treacle)
- 3 cups (750 ml) buttermilk or kefir, plus a splash more if needed
- Butter or oil and baking paper, for the tins
Preparation
- Preheat the oven to 100°C (210°F). Grease two 1-litre (8 x 4 inch) loaf tins, or one 2-litre lidded tin, and line with baking paper.
- Whisk the rye flour, wheat flour, baking soda and salt together in a large bowl.
- Add the syrup and buttermilk and stir until no dry flour remains. Do not knead: the batter will be thick, sticky and heavy, a little like a stiff porridge. If it is too stiff to stir, add a splash more buttermilk.
- Spoon the batter into the tins, filling them no more than three-quarters full, and smooth the tops.
- Cover each tin tightly with a lid or two layers of foil; a tight seal keeps the bread moist.
- Bake for 7–12 hours, with the small loaves at the shorter end. The bread is ready when it is deep brown, firm to the touch and a skewer comes out clean or with just a few moist crumbs.
- Cool in the tins, then turn out and let the loaves cool completely, ideally overnight, before slicing thinly.
Chef's tips
- Keep the oven at 100°C. Much hotter and the crust dries out and the crumb loses its moist, cakey texture.
- Use a tight lid or foil. Escaping steam dries the loaf.
- Ovens run differently, so check the bread near the end of the time range rather than assuming it needs the full 12 hours.
- Let the bread cool completely before slicing; it slices more cleanly and the flavour settles.
- No buttermilk? Stir 3 tablespoons of lemon juice into 750 ml of milk and leave it for 5–10 minutes. The baking soda needs an acidic liquid to work.
A faster version
If you cannot run an oven overnight, some recipes shorten the bake considerably. King Arthur Baking's version uses an all-rye batter with honey and molasses and bakes for about 2 hours at 160°C (325°F) in a lidded loaf tin. It makes a different, lighter loaf than the slow-baked bread above.
How to serve rúgbrauð
Slice it thin and spread it with plenty of salted butter. It goes well with smoked lamb (hangikjöt), smoked or cured fish, cheese and pickled herring, and it is the traditional partner to plokkfiskur and to hákarl. Its sweetness balances salty, smoky or fermented toppings. For another Icelandic bread, try flatbrauð.
Storage
Wrap the cooled loaf tightly and keep it at room temperature for several days. For longer storage, slice and freeze it, then toast or thaw slices as needed.
Hverabrauð: rye bread baked in the ground
Hverabrauð is rúgbrauð baked by the earth itself. The dough is sealed in a pot and buried in hot, geothermally heated ground. At Laugarvatn Fontana, a geothermal spa on Iceland's Golden Circle, the bread is buried in black sand and left for 24 hours; visitors on the rye bread tour dig up a pot and eat it warm with butter. According to Gliding Grains, the method grew out of fuel scarcity after the deforestation that followed settlement.
Rúgbrauð FAQ
Why is Icelandic rye bread sweet?
The batter is sweetened with syrup, and the long, low bake caramelises those sugars, giving a flavour closer to dark cake than to sour rye bread. The sweetness is intentional; it balances salty toppings.
Do I need yeast or a sourdough starter?
No. Rúgbrauð is a quick-bread-style batter raised with baking soda and the acidity of buttermilk or kefir.
Can I bake it faster?
Yes, see the faster version above, but the overnight bake gives the classic dense, caramelised loaf.
Sources
The proportions here are in line with published Icelandic-style recipes, including those below. Oven temperatures and times vary, so treat the bake time as a range.
About Sigrún Ólafsdóttir
Sigrún grew up baking rúgbrauð with her grandmother in Akureyri and has spent the last decade collecting recipes from kitchens all over Iceland. She writes Icelandic MAT's recipes, one dish at a time.