Combine water, and brown sugar and yeast in the bowl of a standing mixer fitted with the dough hook. Let stand for 5 minutes (until foamy). (Or put it in a large bowl and mix by hand).
Once yeast is proofed, add melted butter and milk to the yeast mixture and mix on low speed with dough hook until just combined.
Add flour and salt and mix with dough hook until flour is fully incorporated.
Knead in a mixer until the dough forms a slightly tacky, but firm ball.
Lightly oil a large bowl, place the dough in the bowl, cover with a damp towel and let it rise in a warm place for one hour or until doubled in size.
Once dough is risen, preheat oven to 400 degrees Fahrenheit (204 degrees Celsius).
Lightly oil or grease a large baking sheet, or line it with a silicone baking mat (do not use parchment paper).
YOU ARE GOING TO NEED A WATER BATH
Remove the dough from the bowl and gently press out the air bubbles. Do not let it rise)
Carefully place one of the balls into the boiling baking soda water. Boil for 45-60 seconds on each side, turning it once to guarantee both sides are covered. Remove the dough from the baking soda bath with a slotted spoon, shake off the excess water from the dough and place it on an oiled baking sheet.
Immediately sprinkle coarse sea salt over the bread to your specific tastes, and use a knife to cut a small "X" on the top of the bread.
Repeat with second ball of dough, then straight from boiling water into the oven.
Bake the bread for 22-25 minutes, rotating the baking sheet once halfway through. The bread is done when the outside is golden brown, and the loaf sounds hollow when hit with a wooden spoon.
Once removed from the oven, immediately brush the melted butter over the loaves to guarantee a soft crust. Transfer to a wire rack to cool just enough to enjoy!