Basler Mehlsuppe is Basel, Switzerland’s signature dish. Its name means flour soup and it’s made with browned flour, beef stock, onions, sometimes red wine, and is finished with grated Swiss cheese such as Gruyère.
Mehlsuppe is traditionally served at Basel Carnival, or Fasnacht, which is the Christian celebration that comes right before Lent. The Fasnacht celebration in Basel is the largest in Switzerland and begins at 4 am on the first Monday after Ash Wednesday and proceeds with a parade throughout the old town featuring painted lanterns.
Also at 4 am as the celebration kicks off, one must partake in a bowl of steaming Basler Mehlsuppe. Although this flour soup is especially important to this holiday celebration, it’s such a nationally loved soup that it’s enjoyed year round throughout Switzerland.
The components of the soup are very reminiscent of the ingredients in French onion soup, however, the approach and results are quite different. Here, the flour really is the star and the onions are the supporting cast.
The final flourish of grated Gruyère cheese, definitely propels the soup to another level of flavor. I would not recommend skipping it unless you have an aversion to delicious cheese.
The key is in the roux
There are a couple of general approaches to making this very simple Swiss flour soup. The first is to brown the flour dry in a pan. It’s a bit easier to burn the flour with this method, which is why I’m using the other method, which is basically to make a very dark roux with butter and flour and cook that until it’s browned.
Cooking flour to brown it (in this case in a dark brown roux) really helps develop a lot of flavor and is actually one of the building blocks in Cajun cooking (unrelated but useful information to understand connections between cuisines). If you’ve ever eaten gumbo or étouffée, it started with a dark roux, just like in this mehlsuppe recipe.
Also, culinary fun fact. The longer/darker you cook a roux the less thickening power it has. So although it develops a richer, more intense, toasty flavor, it doesn’t thicken to the same viscosity as a white or blond (less cooked) roux.
- Flour: Basler mehlsuppe is literally flour soup, so the flour really is the star. Plain all-purpose flour is perfect for this purpose.
- Beef Stock/Broth: If you have homemade beef broth or stock, definitely use it, however good quality store-bought beef broth or stock work well too! With such a minimal number of ingredients you just want to make sure they are better quality for the best results.
- Red Wine: Red wine is often included in mehlsuppe, and the amount can range from a couple tablespoons to more. You can omit this ingredient if needed.
- Onions: The onions are really the only solid items you'll find in this flour soup (once the cheese melts). Regular brown or white onions work fine, but use whatever you have.
- Cheese: I really can't imagine this Basler mehlsuppe without the cheese, but also I really love cheese! Adding grated Gruyère to the top really enhances the flavor and adds another texture to what is otherwise a very simple soup. You could use any Swiss or Alpine style cheese here.
How to make it
Melt butter in a medium pot over medium-low heat. Whisk in flour.
Continue to cook, stirring regularly, until the flour is a dark caramel brown, about 35 to 40 minutes (PHOTOS 1-2).
Add thinly sliced onion, stirring to coat and cook for another couple minutes.
Slowly add beef stock, whisking constantly to ensure a smooth mixture. Add a splash of red wine (PHOTO 3). Raise the heat to bring it to a boil, then lower to a gentle simmer and continue to simmer, with the lid slightly ajar, for 1 hour to develop the flavors (PHOTO 4).
Season with salt, pepper, and nutmeg. Divide mehlsuppe into serving bowls and garnish with grated cheese before serving.
Please scroll to the bottom of the post for the full recipe (in a printable recipe card) including ingredient amounts and detailed instructions.
This mehlsuppe recipe makes four smaller cup size servings, but can also serve two larger bowl size servings, if you prefer.
Although I usually like to whisk the flour into melted butter to start my roux (and later whisk liquid into my roux to avoid lumps), my favorite tool for cooking the roux longer is a wooden spoon. It helps get into the edges of the pot to ensure none of the roux sticks or burns.
I used the large holes on a box grater to grate my cheese, yielding larger strips. You could, however, use a finer grater (like a microplane) to yield a finer grate on your cheese. It all comes down to personal preference and which kitchen tools you have in your arsenal.
Other recipes you may like
- Soupe de Chalet (Swiss Cheese and Potato Soup)
- Älplermagronen (Swiss Alpine Macaroni and Cheese)
- Ghackets mit Hörnli (Swiss Macaroni with Meat Sauce)
- Schinkengipfeli (Swiss Ham Croissants)
- Basler Läckerli / Leckerli (Swiss Spiced Cookie Bars)
Tried this recipe? Please leave a star ⭐️⭐️⭐️⭐️⭐️ rating in the recipe card below and/or a review in the comments section further down the page. You can also follow me on social media on Facebook, Instagram, and Pinterest!
Basler Mehlsuppe (Swiss Flour Soup from Basel)
- 55 grams (4 tablespoons) unsalted butter
- 60 grams (½ cup) all-purpose flour
- 1 medium onion thinly sliced
- 1 quart (4 cups) beef stock or good quality beef broth
- 2 tablespoons red wine
- Kosher salt and freshly ground black pepper
- Freshly grated nutmeg
- 50 grams (about ¾ cup) shredded Gruyère cheese (or as desired)
- Melt the butter in a medium pot over medium-low heat. Whisk in the flour and continue to cook, stirring regularly, until the flour is a dark caramel brown, about 35 to 40 minutes. Add the onion, stirring to coat and cook for another couple minutes.
- Slowly add the beef stock, whisking constantly to ensure a smooth mixture. Add the red wine, then raise the heat to bring it to a boil, then lower to a gentle simmer and continue to simmer, with the lid slightly ajar, for 1 hour to develop the flavors.
- Season with salt, pepper, and nutmeg. Divide into serving bowls or cups and garnish with grated cheese before serving.
- This mehlsuppe recipe makes 4 smaller cup size servings, but can also serve 2 larger bowl size servings, if you prefer.
- If you have homemade beef broth or stock, definitely use it, however good quality store-bought beef broth or stock work well too! With such a minimal number of ingredients you just want to make sure they are better quality for the best results.
- Red wine is often included in mehlsuppe, and the amount can range from a couple tablespoons to more. You can omit this ingredient if needed.
*All nutritional information is based on third-party calculations and should be considered estimates. Actual nutritional content will vary with brands used, measuring methods, portion sizes and more.*