Save to Pins There's something almost meditative about turning stale sourdough into golden croutons—watching them transform from humble bread cubes into crispy, tangy soldiers ready to crown a bowl of caramelized onions. My grandmother used to save every heel and forgotten slice, insisting nothing was wasted in her kitchen, and I finally understood why when I tasted a perfectly made crouton floating in that dark, luxurious broth.
I made these for the first time on a gray January evening when friends were coming over and I'd somehow convinced myself that French onion soup at home was manageable. The moment those croutons hit the broiler, my kitchen filled with this smell—toasty, garlicky, almost nutty—and I knew I'd landed on something special. Everyone tilted their spoons toward the cheese-crowned croutons first, and nobody left a single one behind.
Ingredients
- Sourdough bread (4 cups, about 200 g), cut into 1-inch cubes, preferably day-old: Day-old bread is your secret weapon—it's drier and will crisp up beautifully rather than turning dense.
- Olive oil or unsalted butter, melted (3 tbsp): I lean toward olive oil for its fruity character, but butter brings an extra richness that makes these almost addictive.
- Garlic clove, minced (1): One clove is enough to perfume without overwhelming; fresh is non-negotiable here.
- Sea salt (1/2 tsp): Don't skip this—it wakes up every other flavor.
- Freshly ground black pepper (1/4 tsp): The grind matters more than you'd think; it should look like tiny black jewels, not dust.
- Dried thyme or herbes de Provence, optional (1/4 tsp): If you add this, you're leaning into French tradition; if you skip it, you're letting the sourdough shine.
- Gruyère or Emmental cheese, grated (1/2 cup, about 50 g), optional: This is where the magic lives—melted into hot croutons, it becomes almost silken and adds an umami depth that makes people wonder why they taste so good.
Instructions
- Heat your oven and prep:
- Preheat to 375°F (190°C) and line a baking sheet with parchment paper. This temperature is the sweet spot—hot enough to crisp the bread, gentle enough that the garlic won't burn.
- Build the coating:
- In a large bowl, whisk together olive oil (or melted butter), minced garlic, salt, pepper, and herbs if using. You want this mixture fragrant and emulsified, which only takes about a minute of stirring.
- Coat every piece:
- Add your sourdough cubes and toss everything together until each piece glistens with the oil mixture. Use your hands if you need to—it's the fastest way and you'll feel when every cube is covered.
- Spread and bake:
- Arrange the cubes in a single layer on your prepared baking sheet (they need room to breathe or they'll steam instead of crisp). Bake for 15–18 minutes, stirring once halfway through, until they're golden and sound crunchy when you tap them together.
- Cheese moment (if you're going there):
- If using cheese, scatter it over the hot croutons immediately after removing them from the oven, then return for 2–3 minutes until it's melted and bubbly. The residual heat does the work.
- Cool slightly before serving:
- Let them sit for a minute or two—they'll crisp up even more as they cool, and you won't burn your mouth.
Save to Pins I learned the hard way that hot croutons falling into hot soup can slip down and disappear, which is why I now always let them cool first and then nestle them on top as the final touch. There's something about that moment—when someone lifts a spoon and gets a perfect bite of the cheese-crowned crouton, broth, and melted onions all together—that feels like the entire recipe was worth it.
Why Day-Old Bread Matters
Fresh sourdough has too much moisture and will puff up instead of crisping. Day-old bread has already begun to lose moisture naturally, so it dries out in the oven and becomes genuinely crunchy. If you only have fresh bread, you can slice it and let it sit uncovered for a few hours, or even spread it on a baking sheet and dry it in a low oven first—it's an extra step, but worth it.
Storage and Make-Ahead Magic
Croutons are forgiving and actually improve with planning. Make them a day or two ahead, let them cool completely, and store in an airtight container—they'll stay crisp and even develop more flavor as the garlic settles in. When you're ready to use them, just warm them in a 300°F oven for about 5 minutes to restore their crunch, especially if they've picked up any moisture from the air.
Flavor Swaps and Experiments
While this recipe is built around classic French onion soup pairing, sourdough croutons are adaptable. Try swapping Gruyère for Comté (nuttier), Swiss (milder), or Fontina (more complex). You can also add a pinch of smoked paprika or swap fresh thyme for rosemary if you want to drift into different territory. The beauty of homemade is that you're never locked into one interpretation.
- Rub the raw bread cubes with a halved garlic clove before tossing with oil for an even deeper garlic presence.
- For extra richness, brush each cube individually with the oil mixture using a pastry brush instead of tossing—tedious but theatrical.
- Make croutons when you need them most, but remember they're also brilliant on salads, scattered over soups, or simply eaten as a snack.
Save to Pins These croutons are proof that the best garnishes don't come from a box. They're something you'll want to make again and again.
Questions & Answers
- → What type of bread works best for these croutons?
Day-old sourdough bread cut into 1-inch cubes ensures the croutons bake up crisp without becoming too soft.
- → Can I use butter instead of olive oil?
Yes, melted unsalted butter offers a rich flavor and helps the croutons brown nicely.
- → How do I add extra flavor to the croutons?
Rubbing the cut bread with a halved garlic clove before cubing enhances the garlic aroma throughout.
- → What cheese pairs well for topping the croutons?
Gruyère or Emmental cheese melts beautifully, adding a creamy, nutty richness when sprinkled on hot croutons.
- → How should I store leftover croutons?
Keep croutons in an airtight container for up to 3 days to maintain their crispness.