In a large mixing bowl, mix 2 tablespoons warm water with the yeast to dissolve it. Then stir in the remaining warm water and brown sugar. Place bowl on a mixer and using a dough hook, gradually add the flour and continue mixing until it forms a ball. Turn it out onto a work surface and knead the dough to make it smooth. Use enough flour on your work surface so the dough is not sticky.
Preheat oven to 475 degrees F.
Butter 2 sheet pans. Bring 2 quarts of water and the baking soda to boil in a large saucepan. Cut dough up into golf ball size pieces. Then roll them into 1/2-inch thick worms. Form a U then cross the ends, twisting at the middle. Fold the ends back down to meet the U (which is now an O) and press to secure the dough. Drop it into the boiling water for 30 seconds then fish it out and place it on the greased sheet pan. Sprinkle with kosher salt. Repeat with the rest of the dough. Bake for 8 minutes or until golden brown.