Crispy on the outside, light and fluffy on the inside. These are hands-down the best waffles you'll ever make.

In a large bowl, whisk together the sourdough discard, egg yolks, melted butter, milk, sugar, and vanilla.
Add the flour, baking powder, baking soda, and salt. Stir until just combined.
In a separate clean bowl, beat the egg whites with an electric mixer until stiff peaks form.
Gently fold the egg whites into the batter in two additions. This is the secret to ultra-light waffles.
Preheat your waffle iron and grease lightly.
Pour the recommended amount of batter for your waffle iron and cook until golden and crispy, usually 3-5 minutes.
Serve immediately, or keep warm in a 200°F oven on a wire rack while you cook the rest.