Combine the water, honey, and kosher salt in a small bowl, and sprinkle the yeast on top. Allow to sit for 5 minutes or until the mixture begins to foam.
In a large bowl, combine the flours, and then make a well in the center. Stir the butter into the yeast mixture, and pour into the well in the flour. Stir until the wet ingredients are incorporated into the dry ingredients. Once mixed, I knead the dough for a minute or two right in the bowl. You may sprinkle with a little flour if the dough seems too sticky.
Once you have a smooth ball of dough, remove it from the bowl, clean the bowl, and then oil the bowl well. Return the dough to the bowl, flipping to lightly coat in the oil. Cover with plastic wrap, and place in a warm place for approximately 50 to 60 minutes or until the dough has doubled in size.
Preheat the oven to 450 degrees F. Line 2 baking sheets with parchment paper and lightly brush with the oil. (If you don’t do this, the dough will stick to the parchment paper like glue. Trust me, I know!) Set baking sheets aside.
Bring the 10 cups of water and the baking soda to a rolling boil in a large pot.
In the meantime, divide the dough into 8 equal pieces. Using your hands, roll out each piece of dough into a roughly 24-inch rope. (see notes) Make a U-shape with the rope and, holding the ends of the rope, cross them over each other and press onto the bottom of the U in order to form the shape of a pretzel. Feel free to make circles, letters, rods, peace signs, or any other shape you desire. If you make thinner pieces, they will most likely cook faster, so check earlier than the recommended cooking time. Place the rolled pretzels onto the greased, parchment-lined baking sheets.
Using a large, flat spatula, place the pretzels into the boiling water, two at a time, for 30 seconds. Remove them from the water using a spatula or large, slotted spoon that will allow the water to drain. Return to the baking sheet, brush the top of each pretzel with the beaten egg yolk and water mixture, and sprinkle with the pretzel or sea salt.
Bake in the preheated oven until the pretzels are dark golden brown in color, approximately 12 to 14 minutes. I check after 10 minutes, rotating the pans if one side appears to be browning faster than the other. You want them nicely browned to ensure they are cooked through in the thicker sections.
Transfer to a rack or allow to cool on the baking sheets for at least 5 minutes before serving. Enjoy warm with your favorite mustard, if desired.
Leftovers will keep wrapped well and stored in the refrigerator. Reheat gently in the oven or toaster oven. Cooked pretzels may also be frozen.
