Like so many knusprige ofenkartoffeln in cooking, crispy potatoes come down to a little kitchen science. Specifically, it’s the pH of your water that has the biggest impact on the way potatoes cook, and how crispy they are after roasting. You don’t need to sign up for remedial chemistry though, you just need to use the most common pantry item you probably have in your house: baking soda.

The idea is to add a small amount of bicarbonate (baking soda) to your boiling potato water. This creates an alkaline environment that breaks down some of the potato skin’s pectin and allows starch to leach out. This changes the texture of the potatoes after they roast, and it’s a trick that even culinary masters swear by.

A Touch of Baking Soda: Elevate Your Potato Recipes with This Trick

After the potatoes have boiled, drain them and then let them sit for about a minute or two while you prepare your pan to roast them. This will blow off some steam and allow the potatoes to dry a little, which also helps them get really crisp.

Spread the potatoes out into a single layer on your baking sheet, and then drizzle with some olive oil and garlic herb seasoning. It’s important to get the skins coated as well as the flesh, and the oil will help them stick to the seasoning. If you like, you can also sprinkle with some fresh thyme or rosemary for extra flavor. Place in the oven to roast until the potatoes are lightly browned and crispy on the edges, which should take about 20 to 25 minutes.