If you’re after truly crispy potatoes, this is the step you didn’t know you were missing!
Fermenting potatoes before roasting doesn’t just preserve them, it changes them. A short ferment in a simple salt brine helps break down surface starches, which leads to better browning and an incredibly satisfying crunch in the oven. The inside stays fluffy, the outside gets deeply golden, and the texture is on another level.
This isn’t about probiotics (roasting will eliminate many of them) as much as it is about texture. It’s a small extra step that makes a big difference, especially if crispy roasted potatoes are a regular part of your meal plan.
How to ferment potatoes
• Pack cubed potatoes or fries into a jar
• Make a 2% brine: 1 tsp fine sea salt (~5g) per 1 cup water
• Pour brine over potatoes
• Tap the jar/use a chopstick to release air bubbles
• Add a weight + airlock
• Ferment 3 days at room temp
Before roasting
• Drain, rinse, and dry very well
• Toss with oil + seasonings (skip salt for now)
Roasting
• Spread on a pan in a single layer
• Roast at 425°F, flipping once, until deeply golden and crisp
• Taste first, then salt (they absorb some salt during fermentation)
Storage & Tips
You can ferment the potatoes up to a few days in advance and keep them submerged in the refrigerator until ready to roast. Once roasted, they’re best enjoyed fresh while the exterior is at peak crispiness.
This method works beautifully for breakfast potatoes, fries, or roasted cubes served alongside dinner. It’s a simple technique that elevates an everyday staple and once you try it, it’s hard to go back.
I hope you give them a try!
