In the bowl of a stand mixer, add the water, sugar, and salt. Stir to combine. Then sprinkle the yeast over the water and let sit for 5 minutes.
Add the flour and butter to the yeast mixture. Using the dough hook, stir until combined on speed 1.
Increase to speed 2 and allow to knead for about 4 minutes until the dough pulls away from the sides of the bowl.
Remove the dough from the bowl and spray the bowl with non-stick cooking spray. Place the dough back in the bowl and cover it with a piece of plastic wrap.
Let rise until double in bulk. This will take about an hour. I place mine in a 170 degree oven and it was ready in about 30 minutes.
Position the 2 racks in your oven in the center and preheat to 450 degrees. Line 2 baking sheets with parchment paper.
Add 10 cups of water to a stock pot along with the 2/3 cup baking soda. Bring to a boil.
While waiting to boil shape dough. Spray work surface with non-stick cooking spray. Divide dough into 12 pieces. Roll each piece out in to about an 18 inch rope. Fold each rope in half and connect both ends together and twist together.
Drop each into the boiling water mixture for 30 seconds each. Remove from water with a slotted spoon allowing excess water to drip off. Place on the lined baking sheets.
Brush the tops of each with the egg yolk that has been beaten with the 1 Tbsp water. Bake at 450 degrees for 12-14 minutes rotating plan half way through the cooking process.
Remove from oven and brush with melted butter and sprinkle with kosher salt. Be generous with the salt. Allow to cool for 5 minutes and then serve. Makes 12 pretzels.