Easy Finnish Rye Flatbread (Rieska) with Sourdough Discard

Stack of Finnish rye flatbread (rieska) with sourdough discard, topped with melting butter, served on a wooden board in a cozy Nordic kitchen setting.
This traditional Finnish flatbread recipe, known as Rieska, is a quick and wholesome way to use up sourdough discard. Made with hearty rye flour and oats, this bread is soft, slightly tangy, and ready in under 30 minutes — perfect alongside soups, stews, or simply served warm with butter.
Prep Time 10 minutes
Cook Time 15 minutes
Total Time 25 minutes
Course Bread, Side Dish
Cuisine Finnish
Servings 9 servings
Calories 160 kcal

Equipment

  • 9×13” or quarter-sheet baking pan
  • Parchment paper
  • Dough whisk or spatula
  • Mixing bowl
  • Pastry cutter or forks
  • Measuring cups and spoons
  • Liquid measuring cup

Ingredients
  

  • ½ cup rolled oats
  • 1 cup rye flour
  • ¼ cup all-purpose flour
  • 2 tsp baking powder
  • ½ tsp baking soda
  • 1 tsp fine sea salt
  • 2 tbsp granulated sugar
  • cup sourdough discard (unfed starter)
  • 4 tbsp unsalted butter, softened
  • 1 cup whole milk

Instructions
 

  • Preheat oven to 500°F (260°C). Line a 9×13-inch or quarter-sheet pan with parchment paper and lightly grease it.
  • In a large mixing bowl, combine oats, rye flour, all-purpose flour, baking powder, baking soda, salt, and sugar.
  • Add softened butter in chunks. Use a pastry cutter (or two forks) to cut the butter into the dry mix until it resembles coarse crumbs.
  • Add the sourdough discard and lightly mix it into the dough.
  • Pour in the milk and stir to form a sticky dough.
  • Transfer the dough into the prepared pan and spread evenly with wet hands.
  • (Optional) Let rest for 30 minutes for extra rise and tangy flavor.
  • Bake for 12–15 minutes, until lightly browned and springy.
  • Cool for 10 minutes, then slice and serve warm.

Notes

Step-by-step process of making Finnish rye flatbread (rieska) with sourdough discard, from mixing ingredients to baking.
Looking for a quick and wholesome way to use up that sourdough discard? Discover Finnish Rieska, a traditional rye flatbread that’s hearty, rustic, and delightfully easy to make — no rising or kneading required! 🇫🇮💛

What is Rieska? A Taste of Finnish Tradition 🇫🇮

Rieska is a traditional Finnish flatbread that dates back centuries. Originally made by rural families in Northern Finland, it was a humble, no-yeast bread baked daily using whatever flour was on hand — typically rye, barley, or even potato. This bread has remained a staple in Finnish households thanks to its simplicity, speed, and versatility.
Unlike yeasted bread, rieska is unleavened or only lightly leavened, resulting in a soft yet dense texture. It’s typically baked fresh and eaten the same day — still warm, slathered in butter, or served with soups and stews. Today, we’re giving this classic a modern twist by using sourdough discard — a tangy, eco-friendly addition that reduces food waste while adding complex flavor.

⭐ Why You'll Love This Recipe

  • No rise time – ready in under 30 minutes
  • ✅ Uses leftover sourdough discard
  • ✅ Packed with fiber-rich rye and oats
  • ✅ Naturally egg-free
  • ✅ Ideal for dipping, buttering, or topping with cheese

🛠️ Tools & Equipment

To make this easy rye flatbread, you'll need:
  • 9×13” pan or quarter-sheet baking pan
  • Parchment paper
  • Dough whisk or sturdy spatula
  • Large mixing bowl
  • Pastry cutter (or two forks)
  • Measuring cups & spoons
  • Kitchen scale (optional but recommended)
  • Liquid measuring cup

🧾 Ingredients

  • ½ cup (45g) rolled oats
  • 1 cup (113g) rye flour
  • ¼ cup (30g) all-purpose flour
  • 2 tsp baking powder
  • ½ tsp baking soda
  • 1 tsp fine sea salt
  • 2 tbsp (25g) granulated sugar
  • 1¼ cup (200g) sourdough discard (unfed)
  • 4 tbsp (57g) unsalted butter, softened
  • 1 cup (240g) whole milk
Optional Substitutions:
  • Swap rye for barley flour for a more traditional variation.
  • Use plant-based milk and vegan butter for a dairy-free version.

👩‍🍳 How to Make Finnish Rieska with Sourdough Discard

Step 1: Prep the Oven & Pan

Preheat your oven to 500°F (260°C) — yes, really! 🔥 Line a 9×13” pan or quarter-sheet pan with parchment paper and lightly grease it.

Step 2: Mix the Dry Ingredients

In a large bowl, combine the oats, rye flour, all-purpose flour, baking powder, baking soda, salt, and sugar. Whisk until evenly mixed.

Step 3: Add Butter & Discard

Add softened butter in small pieces. Use a pastry cutter or two forks to incorporate it until the mixture resembles coarse crumbs.
Now add the sourdough discard and cut it into the dough — it’s okay if it's not fully blended yet.

Step 4: Add Milk & Combine

Pour in the milk and mix thoroughly using a spatula or dough whisk. The dough will be very sticky — that’s normal!

Step 5: Spread the Dough

Transfer the dough into the prepared pan and spread it evenly using wet hands or a spatula.
Optional: Let the dough rest at room temperature for 30 minutes, or refrigerate it for a few hours. This allows mild fermentation for a tangier flavor and improved texture.

Step 6: Bake

Bake for 12–15 minutes, until the top is golden and springy to the touch. Let cool in the pan for 10 minutes, then slice into squares and serve warm. 🧈

🍲 How to Serve Rieska

Rieska is wonderfully versatile. Serve it:
  • Warm with butter and flaky salt
  • Alongside hearty soups like salmon chowder or lentil stew
  • Topped with cheese, smoked salmon, or herbed cream cheese
  • Toasted with jam or honey for a cozy breakfast

🧊 Storage Tips

  • Store leftovers in an airtight container at room temperature for up to 3 days.
  • Freeze slices in a zip-top bag for up to 3 months. Reheat in a toaster or oven for best results.

🧠 FAQs

Can I Use Fresh Starter Instead of Discard?

Yes, but you’ll get a stronger rise and less tang. Discard is ideal for flavor without the yeast activity.

Why Bake at 500°F?

Rieska is meant to bake quickly and hot, giving it a soft interior and slightly crisp edges — think of it like rustic Finnish pizza crust.

Can I Double the Recipe?

Absolutely! Use a half-sheet pan and increase baking time by 2–3 minutes.

🌾 Why Sourdough Discard Works in Rieska

Rieska traditionally uses buttermilk, which reacts with baking soda for lift. Sourdough discard is also acidic, making it a perfect substitute! It contributes tangy flavor, tender texture, and natural leavening — plus, it helps reduce food waste in your kitchen. ♻️

📌 Save for Later

Pin this recipe to your “Easy Sourdough Recipes” or “Nordic Baking” board so you always have a quick bread option ready!
Keyword Finnish bread, quick bread, rieska, rye flatbread, sourdough discard
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