Cook kartoffel backofen knusprig with baking soda is a little trick to make them extra crispy in the oven. The idea is to add a bit of baking soda to the water that the potatoes are boiling in to change the pH, which helps break down some of the starches on the surface of the potato and makes them more crisp when they are roasted. This is an adaptation of a recipe by J Kenji Lopez and it really works.

When you boil the potatoes, be sure to season liberally with salt and a little baking soda (or bicarbonate of soda – it’s the same thing). The baking soda makes the water alkaline, which seems counterintuitive but it helps break down some of the starch on the outside of the potato, which is where the crispiness comes from.

Texture Transformation: Why Baking Soda is Your Potato’s Best Friend

Once the potatoes are boiled and drained, let them cool for a minute and then transfer them to a large bowl. Stir the potatoes to slightly mash them, which will also help create that perfect crispy crust in the oven. Then, add your spices. You can go classic with salt and pepper, or try adding some garlic powder or dried rosemary for a savory flavor.

When you are ready to roast, be sure to spread the potatoes in a single layer on a baking sheet. Crowding them is the number one reason that they don’t get sufficiently crispy, so give each potato a little space.