The secret to seriously crispy natron kartoffeln potatoes is a simple kitchen science experiment: cook your potatoes with baking soda. Baking soda, or bicarbonate of soda (BOD) as it’s known in many countries around the world, is a natural tenderiser and a deodoriser. It also has the unique ability to lower the pH of water, which makes it an ideal ingredient for parboiling potatoes. This is a necessary step in making roasties with shatteringly crisp skins as it breaks down the starch of the potato’s exterior.
Add a tablespoon of baking soda to your boiling water and give it a stir. Parboil your potatoes for 15-20 minutes or until they can be pierced with the tip of a knife but still have some resistance. Drain and leave to cool until you’re ready to preheat the oven.
Potatoes Transformed: Discover the Science Behind Baking Soda Cooking
Adding the BOD to your water alkalizes it, which helps break down pectin in the potatoes and allows for more surface starch to release. This in turn makes your potatoes a lot crispier.
Once your potatoes have cooled down enough to handle, pat them dry and place on a baking sheet in a single layer. Season with a good amount of salt and drizzle over some oil. I love to use olive oil, ghee or duck fat but vegetable oils will do just as well. Place the tray into a hot oven and roast until golden. Be sure to check them halfway through to ensure they’re cooked. If not, roast for a few more minutes before checking again.