In a large bowl whisk together the flour, instant yeast, sugar and salt. Add the butter in small pieces and toss together with the flour mixture. Add the water and combine with your hands until the dough comes together.
Empty the dough onto a work surface and knead the dough until it is smooth (about 5 minutes). Cover the dough with a kitchen towel and let rest for 15 minutes.
Uncover the dough and divide into 8 equal portions (approx. 100g each). Cover the divided dough with a kitchen towel and let rest for 10 minutes.
In the meantime, line a large baking sheet with parchment paper or silicone baking mat and set aside.
To form each pretzel, take one ball of dough and flatten it into a rectangle with the heel of your hand. Fold one long side into the middle then seal the seam with the heel of your hand. Fold the other long side into the middle and seal that seam with the heel of your hand. Fold in half and seal the seam against the work surface with the heel of your hand.
With the sealed seam side facing up, roll the dough out to approximately 2ft long using the palms of both hands. Apply more pressure to the edges of the dough to create thin strands with a thick center.
Turn the seam side down and bring both strands towards you on the work surface. Take the end of each strand in one hand, cross them over each other twice, flip the ends over and press each end deeply into either side of the fat middle. Transfer the shaped pretzel to the lined baking sheet.
Repeat the shaping for each piece of dough. Let the pretzels rest at room temperature, uncovered, for approximately 30 minutes (or until pretzels have swelled and look poofy). This could take longer or shorter depending on how cool or warm your room temperature is and if you used room temperature water or calculated the water temperature you needed using the DDT (see notes below).
Transfer the entire baking sheet to the freezer and freeze uncovered for a minimum of 1 hour (or overnight).
Preheat the oven to 425 degrees F. In a large pot, bring the water and baking soda to a slow boil, stirring once to help the baking soda dissolve. Remove the baking sheet from the oven and loosen each pretzel from the parchment or silicone baking mat before proceeding.
Place two pretzels at a time in the boiling baking soda solution and boil for 20 seconds. Remove the pretzels with a large slotted spatula and return them to the baking sheet. Repeat with remaining pretzels.
Using a very sharp knife or bread lame, deeply slash the belly of each pretzel horizontally then sprinkle course salt over the belly of each pretzel.
Bake for 15-18 minutes or until pretzels are a deep brown. Remove and transfer to a wire rack to cool. Serve warm or at room temperature. Freeze any pretzels that will not be eaten on the same day.