In a mixing bowl, combine the lukewarm water, active dry yeast, and sugar. Let it sit for about 5-10 minutes until it becomes frothy.
In a separate bowl, whisk together the salt and 4 cups of all-purpose flour.
Add the yeast mixture to the flour mixture along with the lukewarm milk. Stir until the dough begins to come together.
Transfer the dough to a lightly floured surface and knead it for about 5-7 minutes, or until smooth and elastic.
Place the kneaded dough in a lightly greased bowl, cover with a towel, and let it rise for about 1 hour, or until it doubles in size.
Preheat your oven to 450°F (230°C). Punch down the dough and divide it into 8 equal pieces. Shape each into a pretzel.
In a large pot, bring 10 cups of water to a boil and add the baking soda. Drop the pretzels into the boiling water for about 30 seconds.
Remove the pretzels, place them on a baking sheet lined with parchment paper, brush with melted butter, and sprinkle with sea salt. Bake for 12-15 minutes.
Allow the pretzels to cool slightly before serving and enjoy them with your favorite dips!