In a small bowl, sprinkle the yeast over 1 cup (237 milliliters) of the warm water. Stir to combine and let sit until frothy, about 10 minutes.

In the bowl of a stand mixer fitted with a dough hook or a large bowl, combine the flour, sugar, and salt. Slowly mix in the yeast with water and butter. If needed, slowly add the remaining ¼ cup (60 milliliters) water to create a soft dough.

On a lightly floured surface, knead the dough until smooth and elastic. Transfer to a large bowl, cover with plastic or a towel, and allow to rise until doubled, 1-2 hours.

Preheat oven to 450˚F (230˚C). Line a baking sheet with parchment or lightly grease.

Once doubled, place the dough on a lightly floured surface and divide in half. Form each half into a smooth large oval, tucking the seams under, and place on the prepared baking sheet. Cover and allow to rest at room temperature for 30 minutes.

Place the 8 cups (2 liters) water and baking soda in a pot and bring to a boil.

Gently place one loaf in boiling water for 30 seconds, turning halfway to coat both sides. Remove with a large slotted spoon to the prepared baking sheet. Repeat with other loaf.

In a small bowl, beat together the egg yolk and water.

Brush each boiled loaf with the egg wash and sprinkle with coarse salt. Cut 3-4 parallel shallow slashes across the top with a sharp knife.

Bake in preheated oven until deep brown and hollow sounding in center, about 15-20 minutes.

Transfer to a wire rack and cool for about 15 minutes before slicing.

This Pretzel Bread is best served the day of baking.