In small bowl, mix the sugar and water. Sprinkle the yeast over the top, and set aside for 10 minutes or until foamy.
In a small saucepan, melt the butter and salt. Set aside.
In a large bowl, add the flour, and make a well in the center. Add the yeast mixture and the butter mixture to the well. Stir together until the flour has absorbed the liquid; then knead in the bowl for 5 minutes. The dough should be smooth and elastic, not stuck to the sides of the bowl.
Oil a clean, large bowl. Form the dough in to a ball, and flip it around in the bowl, until the dough is oiled on all sides. Cover the bowl with plastic wrap, and let the dough rise in a warm place for 45-60 minutes until doubled in size.
Preheat oven to 475° F. Pour 10-12 cups of water into a large saucepan or pot (water should be at least 3 inches deep). Bring the water to a boil on the stove top, stir in the baking soda, and keep at a simmer.
Gently deflate the risen dough with your hand, turn onto a lightly floured surface, and divide the dough into 6 or 12 pieces (depending how large you want the pretzels).
Roll each piece of dough into an 18 inch long rope. If the rope shrinks to a shorter length, let them sit for a few minutes, and roll it into 18 inches again.
Form the pretzel shapes one or two at a time by holding each end of the rope and shape in to a “U” shape, then cross each end over another. Lightly press overlapped dough together.
Immediately after shaping, drop the pretzel into the boiling water for 10 seconds. Hold the pretzel under water for 5 seconds.
Remove the pretzel from the water with a spatula and rest on paper towels (leaving on the spatula) to drain slightly, then place on an oiled baking sheet. Repeat with all pretzels placing them 1″ apart.
In small bowl, whisk the egg yolk and water together. Using your finger, brush egg wash on top of each pretzel (try not to drip egg wash on the pan; it will cause the pretzel to stick). Sprinkle salt on pretzels.
Allow pretzels to rise for 5 minutes. Bake for 10-12 minutes until the pretzels look golden brown. Cool on wire racks at least 5 minutes before eating. Makes six-6 inch or twelve-4 inch pretzels.