Pour the warm water into a large mixing bowl. Sprinkle the yeast on top and let it sit for 5 minutes until it foams.
Stir in the salt and sugar until dissolved.
Gradually add the flour, one cup at a time, mixing with a wooden spoon until a dough forms.
Knead the dough on a floured surface for about 8 minutes until smooth and elastic.
Place the dough in a greased bowl, cover with a towel, and let it rise for 1 hour in a warm place.
Preheat oven to 450°F. Line two baking sheets with parchment paper.
In a large pot, bring 10 cups of water and baking soda to a boil.
Punch down the dough and divide into 8 equal pieces. Roll each into a long rope and shape into a pretzel.
Carefully dip each pretzel into the boiling baking soda water for 30 seconds. Use a slotted spatula to remove.
Place pretzels on prepared sheets. Brush with beaten egg and sprinkle with coarse salt.
Bake for 12–14 minutes or until deeply golden. Cool on a rack for 5 minutes before serving.