In the bowl of a stand mixer, combine the water, sugar and kosher salt. Sprinkle the yeast on top and allow it to sit for 5 minutes or until it begins to foam.
Secure the hook attachment to the stand mixer, then add the flour and butter to the bowl and mix on low until the ingredients are combined.
Increase the speed to medium and knead until the dough is smooth and pulls away from the side of the bowl, 4 to 5 minutes.
Remove the dough from the bowl. Clean the bowl and then grease it with vegetable oil.
Return the dough to the bowl, cover it with plastic wrap and place it in a warm place for 1 hour, or until the dough has doubled in size. (Watch my video for how to proof bread in the dryer.)
Preheat the oven to 450ºF and position the oven racks in the middle two positions in your oven.
Line two sheet trays with lightly oiled parchment paper.
Stir together the 10 cups of water and the baking soda in an 8-quart pot. Bring the mixture to a rolling boil.
While the water comes to a boil, turn the dough onto your work surface and divide it into 12 equal pieces. (Do not flour your work surface; See Kelly's Notes.)
Applying even pressure, roll out each piece of dough into an 18- to 20-inch rope. Fold each rope in half, twisting the two pieces around one another and pressing the ends together. Twist the bottom end around the top, feeding it through the top hole and pressing to secure. (See photos for shaping instructions.) Return the twists to the cookie sheet.
One by one, carefully place each twist into the boiling water for 30 seconds. Remove each twist from the water using a large slotted spoon or spatula(s) and return it to the cookie sheet. Brush the tops of the twists with the egg yolk wash and sprinkle with kosher salt (optional).
Bake the twists until golden brown in color, 12 to 14 minutes, rotating the pans (between racks and turning to rotate pans) halfway through, then remove the twists from the oven and allow them to cool for 5 minutes before serving.