Step 1In the bowl of a stand mixer, or in a large bowl, sprinkle the yeast over the warm water. Stir in the sugar and one-half cup of the bread flour. Set aside until the yeast begins to bubble, about 10 minutes.
Step 2Meanwhile, in a medium bowl, whisk together the remaining bread flour with the rye flour and salt.
Step 3Beat the melted butter into the large bowl with the yeast. Using the dough hook (if using a stand mixer), or a fork or wooden spoon (if mixing by hand), slowly mix in the remaining flour mixture, a spoonful at a time, until all the flour is added and a firm, thick dough is formed.
Step 4Move the dough to a lightly floured board. Knead until it is smooth and elastic, 2 to 3 minutes.
Step 5Remove the dough to a large, oiled bowl. Cover and set aside in a warm place until the dough is almost doubled in size, 45 minutes to an hour.
Step 6Meanwhile, prepare the pretzel wash and heat the oven to 450 degrees.
Step 7Divide the risen dough into 12 pieces, each weighing about 3 1/2 ounces. Form each piece into a ball, pinching the seams together at the base of each ball.
Step 8Slowly roll each ball out into a rope. Roll each out as far as it will go without springing back, then move to the next ball and start rolling it out, giving each rope time to relax. Eventually, roll each of the ropes out to a length of about 24 inches. Twist the ropes to form a pretzel shape, pressing each of the ends into the pretzel.
Step 9Dip each pretzel into the pretzel wash (wear rubber kitchen gloves and goggles if using lye) for 15 to 20 seconds, turning the pretzel over halfway to coat evenly. Remove the pretzel to a greased nonreactive baking sheet and top as desired (if using an aluminum baking sheet, line it with parchment before greasing).
Step 10Repeat until all the pretzels have been dipped and topped, allowing a few inches of space between each pretzel on the baking sheet.
Step 11Bake the pretzels, 1 sheet at a time, in the center of the oven until puffed and a rich golden brown (color will vary depending on the wash), 10 to 14 minutes. Rotate the sheet halfway through baking for even coloring.
Step 12Remove the baking sheet to a rack and set aside until the pretzels have cooled slightly before serving.