Preheat the oven to 250 degrees F. Line 2 baking sheets with parchment paper.
Place the popcorn and pecans in a large mixing bowl. Combine the sugar, butter, corn syrup and salt in a saucepan over medium-high heat. Bring to a boil and continue to boil for 4 minutes. Remove the mixture from the heat and stir in the bourbon and baking soda. Pour over the popcorn and stir well to coat completely. Divide the popcorn in an even layer between the 2 baking sheets.
Bake, gently stirring and rotating the pans about halfway through (after 8 to 10 minutes), until the popcorn is mostly dry and the caramel coating is crisp, 15 to 20 minutes total. Cool completely on the baking sheets before breaking up and serving.