If you love sourdough baking but haven't ventured beyond bread and pizza, Sourdough Flammkuchen might just become your new favourite bake. Crisp, thin, and finished with simple yet indulgent toppings, this Sourdough Tarte Flambée or Flammkueche in Alsace sits somewhere between a white pizza and a flatbread, but with its own distinct personality. It's fast, unfussy, and a brilliant way to use sourdough discard without having to wait for the dough to ferment.

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Alsatian Pizza With Sourdough Twist
Flammkuchen, also known as Tarte Flambée or Flammekueche, comes from the Alsace region of France, right on the French-German border. The name translates roughly to "flame cake", a nod to how it was traditionally baked right on the floor of wood-fired ovens, using the intense heat of their flames to cook the thin dough in minutes.
In Germany, you'll often see it called German Flammkuchen or even described as a kind of German pizza, though it's closer to an unleavened flatbread than pizza dough.
The classic version uses a very simple base of unleavened dough made from flour, water, oil, and salt, topped with crème fraîche, thinly sliced raw onions, and strips of bacon. There's no tomato sauce, no leavening agent, and no attempt at fluffiness - the appeal lies in how crisp and light it is.
Adding sourdough discard to the dough is a natural fit. It doesn't turn this into a yeasted bread or add noticeable rise, but it brings subtle flavour, improved browning, and a gentle tang that works beautifully with creamy toppings and salty bacon. It blends in so seamlessly that you'd never guess this wasn't the real thing - just a slightly more characterful version.
Ingredient Notes
Here's everything you will need for the base and traditional flammkuchen toppings:
- Plain flour (all-purpose flour). Keeps the flammkuchen base crisp and easy to roll thin. Bread flour would make the dough too elastic and chewy for this style.
- Sourdough discard or active sourdough starter. Either works, as long as it's not overly old. Very acidic discard with a dark liquid (hooch) will make the dough too slack and sour.
- Water (lukewarm). Helps bring the dough together smoothly. This is a low-hydration, simple dough.
- Neutral oil. Sunflower or vegetable oil keeps the dough supple without adding flavour. Olive oil works too, but will be more noticeable.
- Crème fraîche. Essential for an authentic flammkuchen base. Full-fat crème fraîche is thick enough not to seep into the dough in a hot oven. Fromage blanc or full-fat sour cream can work in a pinch.
- Bacon lardons or pancetta. Crisped first to remove excess fat. Bacon fat left on the base can make it soggy and unpleasant to eat. For a vegetarian version, top the flammkuchen with asparagus tips (have a look at our Spelt Tarte Flambee With Asparagus recipe) and/ or sauteed mushrooms.
- Onion. Brown, white onions or sweet onions, sliced very thinly, cook quickly and soften without burning.
- Gruyère or Emmental. Both melt beautifully and suit the Alsatian flavour profile. You can use cheddar or a mixture of melty cheeses. Munster is very traditional!
- Nutmeg. Just a pinch lifts the creaminess without overpowering.

Find ingredient quantities, detailed instructions and nutritional information in the recipe card at the bottom of the post.
Step-By-Step Method
1. In a large mixing bowl, combine the flour and salt.
2. In a separate bowl, mix the sourdough starter with lukewarm water and oil.
3. Pour the wet ingredients into the flour mixture and bring together into a rough dough.
4. Tip onto a lightly floured surface and knead for 10-15 minutes until smooth and elastic. The dough should be firm but pliable.
5. Shape into a ball, cover with a tea towel or cling film, and rest at room temperature for 20-30 minutes.
6. Meanwhile, cook the bacon lardons in a frying pan over medium heat until golden. Transfer to a paper towel-lined plate.
7. Preheat the oven to its highest setting (230 °C / 450 °F). If using a pizza stone, preheat it fully.
8. Roll the dough into a very thin rectangle or oval, roughly 25 × 28 cm, using a rolling pin directly on a lightly floured sheet of parchment paper.
9. Transfer to a baking sheet.


10. Spread a thin, even layer of crème fraîche over the dough, leaving a small border.
11. Scatter onion slices, grated cheese, and crispy bacon over the top. Finish with a pinch of nutmeg.


12. Bake for 11-12 minutes until the edges are golden brown and crisp. Slice with a pizza wheel (or cut it with kitchen scissors - trust me, it works, as shown in the video in the recipe card!) immediately and serve hot.

Recipe Tips
- Don't use overly old discard. Over-fermented discard will be too runny, making the dough hard to roll and overly sour.
- Roll it thinner than pizza dough. Flammkuchen cooks fast. Thin dough ensures a crisp base before toppings overcook.
- Slice onions very thinly. Thick slices won't soften in the short bake time.
- Stick to full-fat creme fraiche. Low-fat alternatives release water and can make the base soggy.
- Bake hot and fast. A hot oven mimics the heat of traditional wood-fired ovens and gives the best texture.

Serving Suggestions
Traditionally, tarte flambée is served sliced into squares as a starter, often shared at the table before a main meal.
At home, it works just as well as a main dish. Serve it with:
- A simple green salad with sharp vinaigrette (try our Courgette Ribbon Salad or Pea Shoot Salad)
- A light soup to start
- Or alongside other small plates for a relaxed dinner
Because it's thin and crisp, sourdough flammkuchen is best eaten straight from the oven.
More Sourdough Discard Recipes
Hope you liked this sourdough flammkuchen recipe. If you enjoy using discard in simple, flavour-forward bakes like this Sourdough Flammkuchen, you'll find plenty more inspiration in my other sourdough discard recipes linked below.

Sourdough Flammkuchen (Sourdough Tarte Flambée)
Ingredients
- 100-120 g plain flour* all purpose flour
- ¼ teaspoon salt
- 50 g sourdough discard or active sourdough starter, 100% hydration
- 50 ml lukewarm water
- 1 tablespoon neutral oil like sunflower or vegetable
Topping
- 100 g bacon lardons or pancetta
- 100 g creme fraiche
- 1 brown onion thinly sliced
- 120 g Gruyere or Emmental grated
- a pinch of nutmeg
Instructions
- In a large mixing bowl, combine flour and salt. In a separate bowl or a jug, mix the sourdough starter with water and oil.
- Pour the wet ingredients into the flour mixture and bring together into a rough dough.
- Tip it onto a lightly floured worktop, and knead for 10-15 minutes. TIP: You can prepare the dough in a stand mixer, fitted with a dough hook attachment (stand mixer works better if you are doubling or tripling the recipe though).
- Shape the dough into a ball, cover it with a clean tea towel and rest for 20-30 minutes.
- In the meantime, fry the bacon lardons until golden brown. Transfer them onto a plate lined with paper towel to absorb excess fat.
- Preheat the oven to 230°C (450F). Line a large baking sheet with parchment paper.
- Roll the dough into a thin rectangle, about 25x28 cm (10x11 in) directly on the parchment paper. Then slide it onto the baking sheet.
- With the back of a spoon, spread the crème fraîche leaving a 1-2 cm (½ in) edge. Scatter the sliced onion and cover everything with grated cheese. Finally scatter the fried bacon and sprinkle some nutmeg on top.
- Bake the sourdough flammkuchen for 11-12 minutes. The base should be crispy around the edges (NOTE, the slices will be a lot thinner than pizza and it is not meant to hold shape when held by the edge).
- Slice it onto a large board, slice into squares and serve immediately. In Alsace, I've seen it cut with scissors, rather than sliced with a knife.
Video
Notes
Nutrition










Jess says
This was such a fun recipe! I enjoyed making it and loved that I did not have to wait for my dough to ferment.
Viorica says
Made this with bacon and onions I needed to use up. So crispy and better than the ones we had in Germany. New pizza night favorite.
Ieva Greber says
Same! We prefer it to a regular pizza these days! 🙂
Kimmy says
This sourdough flammkuchen was absolutely incredible. It is such a creative and delicious way to use sourdough discard!
Ieva Greber says
Thank you so much, Kimmy! I’m so pleased you loved it — sourdough discard really does scrub up nicely when there’s crème fraîche, onions and crispy edges involved, doesn’t it?
Ramona says
I will make anything that involves sourdough as it’s so delicious and this recipe looks insane! Thank you for sharing, I cannot wait to try it out!
Gina says
This sourdough flammkuchen sounds crisp, savory, and such a fun way to use discard. Love that it has that white pizza feel but comes together fast without waiting for the dough to ferment.