Preheat the oven to 400F. Grease a baking sheet with butter or oil.
In a large bowl combine instant yeast, lukewarm water, brown sugar, melted butter, and salt. Whisk to combine.
Using a stand mixer with the dough hook or your hands, add flour 1 cup at a time, and mix until thickened.
Once the dough starts coming together, it's time to knead. Turn the dough onto a lightly floured surface and knead for about 5 minutes until the dough is smooth. Cover with a towel and let rest for 10 minutes.
While the dough rests, make the baking soda bath. In a large pot, bring the water and baking soda to a boil.
Once the dough is done resting, use a pizza cutter or dough scraper to cut it into 6 equal sections. Roll each section into a large rope about 20 inches long.
Twist each rope into a pretzel shape. This is done by creating a U shape. Then twist the ropes twice in the middle, and pull the ends of the rope down to the U's bottom.
Dip each pretzel in the baking soda bath for 25 seconds. Do not let them sit in the bath for any longer, or they will begin to develop a metallic taste from the baking soda. Remove the pretzel with a slotted spoon, let the excess water drip off, and set on a prepared baking sheet. Sprinkle with coarse salt.
Bake for 15 minutes until golden brown. Once finished, brush with melted butter and more coarse salt if desired.