In a large mixing bowl combine the flour, sugar, salt, and yeast. Mix until well combined.

Add in the milk and sourdough starter and mix until the dough begins to come together.

Add the water, a tablespoon at a time, until the dough sticks together.

Turn the dough onto a floured surface and knead for 10 minutes or until the dough softens.

Spray a bowl with cooking spray, put the dough in it, and cover. Allow to rise for 1 hour or until the dough has almost doubled.

Line two baking sheets with parchment paper or silpats.

Cut the dough into 8 pieces. Roll each piece into a long rope about a half inch to 3/4 of an inch in diameter and 12 inches in length.

Lay the rope of dough in a u-shape. Twist
the two ends together twice then fold the twisted ends down onto the base of the "u" and gently press in place. Place on the prepared baking sheet.

Cover the pretzels with a towel and let them rest for 20 minutes.

Meanwhile preheat the oven to 400 degrees and pour the water and baking soda in a large pot over high heat until it boils.

Add the pretzels one at a time to the boiling water. Boil for 30-45 seconds then flip it over and boil for 30-45 additional seconds. Remove the pretzel with a slotted spoon and place back on the baking sheet. Repeat with remaining pretzels.

Brush each pretzel with the melted butter and sprinkle with kosher salt. If desired sprinkle with additional toppings.

Bake for 20-22 minutes or until the pretzels are golden brown.

Remove from the oven and cool for 5 minutes before enjoying.