Mac and cheese is one of those things I could make every week and nobody in this house would complain.
This version uses sourdough discard in the cheese sauce, and honestly it’s the only way I make it now. The discard adds just a little tang that cuts through all that richness, you’d never quite put your finger on it, but it’s what makes it taste different from every other mac and cheese you’ve had. Topped with buttery breadcrumbs and baked until golden and bubbling, it’s the kind of dinner that feels like a lot of effort but really isn’t!
It’s a Sunday dinner staple here. Oliver cleans his bowl every time. And if you’ve got discard to use up, it’s a much more exciting option than pouring it down the drain (and you should NEVER do that by the way, unless you want an expensive plumbing bill!). Check out my full collection of sourdough discard recipes for more ideas.
New to sourdough? Start here → Starting with Sourdough: A Beginner’s Guide
This post may contain affiliate links, please read our disclosure policy for details.
Why You’ll Love This Recipe
Try out my cast iron skillet mac & cheese if you are looking for something quick that requires little effort and no sourdough discard!
Ingredients
Recipe Tips
Use room temperature discard: Cold discard can cause the sauce to separate or clump. Let it sit out for 15–20 minutes before using.
Whisk constantly when making the roux: This prevents lumps and ensures a smooth, creamy base.
Shred your own cheese: Pre-shredded cheese contains anti-caking agents that can make the sauce grainy.
Don’t boil the sauce after adding cheese: Keep the heat low to avoid curdling.
Adjust thickness as needed: If the sauce is too thick, add a splash of milk; if too thin, let it simmer a little longer.
Taste before serving: Sourdough discard varies in tanginess, add a pinch more salt or cheese if needed.
Make it ahead: You can make the sauce in advance and store it in the fridge for up to 2 days, just reheat gently before mixing with pasta.
homestead kitchen
Get My Simple Kitchen Printable Bundle
Bring a little order to your from-scratch kitchen. My Simple Kitchen Printable Bundle is filled with practical pages to help you plan meals, track pantry staples, and keep your homestead kitchen running smooth and simple.
New to baking with discard? Be sure to check out my beginner’s sourdough discard bread for another easy loaf that doesn’t require a stand mixer.
Instructions
For the Cheese Sauce
- Cook the pasta: Bring a large pot of salted water to a boil. Add your elbow macaroni and cook just until al dente, tender but still with a little bite. Drain the noodles and set them aside while you prepare the cheese sauce.
- Make the roux: In a medium saucepan over medium heat, melt the butter. Once it’s fully melted and gently bubbling, sprinkle in the flour. Whisk it constantly for about 1–2 minutes to cook out the raw flour taste. The mixture should be smooth and lightly golden, like a creamy paste.
- Stir in milk and sourdough discard: Slowly pour in the milk while whisking to keep everything smooth. Then whisk in your sourdough discard. Keep stirring as the mixture gently heats and thickens (this takes about 5 minutes). You’ll know it’s ready when it coats the back of a spoon.
- Add the cheese and seasoning: Turn the heat to low and stir in the shredded cheddar, grated parmesan, Dijon mustard (if using), salt, and black pepper. Stir gently until the cheese is completely melted and the sauce is velvety smooth.
Baking
- Combine pasta and sauce: Pour the cooked pasta into the cheese sauce and stir until every noodle is coated with that creamy, tangy goodness. You can do this in the saucepan or right in your baking dish if it’s large enough.
- Transfer to baking dish: Lightly butter a 9×13” casserole dish and spoon in your mac and cheese. Spread it out evenly with the back of a wooden spoon.
- Make the breadcrumb topping: In a small bowl, mix the breadcrumbs with melted butter. If you’re using parmesan or a sprinkle of herbs, add them now. Stir until the crumbs are evenly moistened.
- Top and bake: Sprinkle the buttery breadcrumbs evenly over the top of the mac and cheese. Pop the dish into a preheated 375°F oven and bake uncovered for 15–20 minutes, or until the top is golden brown and bubbling around the edges.
- Cool slightly and serve: Let the dish rest for about 5–10 minutes before serving. It helps the sauce settle a bit and makes each scoop easier to serve, and even more satisfying.
FAQ
Recipe Variations & Substitutions
Join the List
Want More Simple Recipes & Seasonal Inspiration?
Get cozy, from-scratch recipes, seasonal homesteading tips, and simple living inspiration delivered straight to your inbox.
Similar Recipes
Baked Sourdough Discard Mac & Cheese
Equipment
- large pot To boil the pasta
- Medium saucepan For the cheese sauce
- Box grater For freshly shredded cheese
- Casserole dish (9×13”): For baking
Ingredients
Mac & Cheese
- 2 cups elbow macaroni
- 3 tbsp butter
- 3 tbsp all-purpose flour
- 2 cups whole milk
- ½ cup sourdough discard
- 2 cups shredded sharp cheddar cheese
- ½ cup freshly grated parmesan cheese
- 1 tsp Dijon mustard optional
- ½ tsp salt
- ¼ tsp black pepper
Breadcrumb Topping
- ¾ cup breadcrumbs
- 2 tbsp butter melted
- 2 tbsp grated parmesan optional
Instructions
- Cook the pasta: Bring a large pot of salted water to a boil. Add macaroni and cook just until al dente. Drain and set aside.
- Make the roux: In a medium saucepan over medium heat, melt the butter. Once melted, whisk in the flour and cook for 1–2 minutes until smooth and golden.
- Add milk and discard: Slowly whisk in the milk and sourdough discard until the mixture is smooth. Simmer over medium heat, whisking frequently, until thickened—about 5 minutes.
- Add cheese and seasonings: Turn the heat to low. Stir in the cheddar, parmesan, Dijon (if using), salt, and pepper. Mix until melted and creamy.
- Combine: Stir the cooked macaroni into the sauce until fully coated. Serve as-is or continue with baked version.
- Bake: Preheat oven to 375°F. Transfer mac and cheese to a buttered 9×13” baking dish. Mix breadcrumbs with melted butter and parmesan (if using), then sprinkle over the top. Bake uncovered for 15–20 minutes or until golden and bubbly. Let cool slightly before serving.
Notes
- Use room temperature discard for easier blending into the sauce.
- Shred your own cheese for the smoothest melt—pre-shredded often contains anti-caking agents.
- Don’t boil the sauce after adding cheese to prevent it from separating.
- Make it ahead: the sauce can be prepped and stored for 1–2 days in the fridge.
Nutrition
Did you make this recipe?
We’d love to see! Tag @the.rootedfarmhouse on Instagram! #therootedfarmhouse
This recipe is a must try! Let me know what you think!