• In a large mixing bowl, combine the yeast, warm water, sugar, and salt, stirring until the yeast is dissolved.
• Let stand for 5 minutes, or until the mixture is bubbly.
• Gradually add the flour until a soft dough forms that is neither sticky nor dry, adding extra flour if necessary.
• Turn the dough out onto a clean work surface and knead until elastic and smooth, about 3 to 4 minutes.
• Place the dough in a lightly oiled bowl and cover with a kitchen towel. Let it rise in a warm place for about 1 hour or until doubled in size.

Form the Pretzels

• Preheat the oven to 400 °F.
• Line a baking sheet with parchment paper and set aside.
• Bring the 7 cups of water and baking soda to a rolling boil in a medium-large saucepan over medium-high heat.
• Punch down the dough and turn it out onto a clean work surface.
• Separate the dough into 8 equal pieces. Roll each piece of dough into a rope about ½ inch thick.

Shape the Pretzels

• Make a U-shape with the rope of dough and bring the 2 ends together, crossing one over the other. Gently press where they cross to adhere to one another.
• Flip the twisted part over so the ends of the rope are touching the bottoms of the U. Gently press again to secure the rope ends to the base of the pretzel.
• Drop 1 pretzel at a time into the boiling water and boil for about 30 seconds.
• Remove it using a slotted spoon and transfer the pretzel to the prepared baking sheet. Repeat this until all of the pretzels have been boiled.
• Sprinkle with the coarse salt and bake until golden brown, about 11 to 12 minutes.
• Allow the pretzels to cool slightly before serving. Serve warm or at room temperature with mustard for dipping.