In a large mixing bowl, combine warm water, yeast, and sugar. Let sit for 5 minutes until frothy.
Add flour, salt, and melted butter to the yeast mixture. Mix until a dough forms.
Knead the dough on a floured surface for about 5 minutes until smooth and elastic.
Place the dough in a greased bowl, cover, and let rise in a warm place for about 1 hour or until doubled in size.
Preheat oven to 450°F (230°C). Line a baking sheet with parchment paper.
In a large pot, bring 9 cups of water and the baking soda to a boil.
Divide the dough into 8 equal pieces. Roll each piece into a rope and shape into a pretzel.
Carefully dip each pretzel into the boiling baking soda bath for 30 seconds. Remove with a slotted spoon and place on the prepared baking sheet.
Sprinkle each pretzel with coarse sea salt.
Bake for 12-15 minutes or until golden brown.
Let cool slightly before serving. Enjoy!