Combine yeast and warm water in mixer bowl, let sit for a few minutes and then stir until yeast is dissolved.
Add salt, sugar, and butter to liquid and stir to combine. Add 2 ½ cups of flour to liquid and knead in mixer with the dough hook. Add the remaining ½ to ¾ cup of flour a tablespoon at a time until the dough is smooth and forms a ball.
When the dough is smooth, place it in a large, oiled bowl. Cover it loosely with plastic wrap and let rest for 30 minutes to an hour in a warm location. It should double in size.
Preheat the oven to 450 F.
Once the dough has doubled in size, turn dough out onto a lightly floured work surface. Divide the dough into 8 equal pieces and roll each piece out into about a 20 inch rope. Form a circle with and twist the ends around one another allowing for about 2 inches of tail on each end. Then fold the ends back over the opposite end and attach to form the pretzel shape. Place on a parchment lined baking sheet and let rest.
Heat 8 cups of water in a large pot until boiling. Add baking soda and stir. Lower pretzels, as many as will fit without crowding, into the pot. Simmer for 15 seconds, then use a slotted spoon to flip the pretzels over and simmer for another 15 seconds. Return boiled pretzels to the baking sheet and repeat with the remaining pretzels.
Sprinkle pretzels with salt and bake until they are browned, about 15 minutes. Remove the pretzels from the oven and immediately brush them with melted butter. Yield is 8 pretzels.