Preheat the oven to 350°F. Prepare a rimmed baking sheet with parchment or a silicone mat; set aside. In a medium bowl, prepare an ice bath; set aside.

In a medium saucepan, bring the water to a boil. Add the baking soda (water will bubble and foam), stirring to dissolve. Add the hazelnuts and boil, stirring occasionally, for 3-4 minutes. Drain and rinse the hazelnuts. Immediately transfer to the ice bath. Slip off the skins with your fingers and transfer to a towel. Blot the hazelnuts dry and transfer to the prepared baking sheet. Bake until lightly golden about 15-20 minutes. Allow the hazelnuts to cool completely before eating or using in a recipe. Store in an airtight container for up to one week or freeze in a vacuum sealed bag for up to one month. Enjoy!