Preheat oven to 250°. Place popcorn, bacon, and peanuts in a lightly greased large bowl.
Melt butter in a large heavy saucepan over medium heat. Stir in brown sugar and next 2 ingredients; bring to a boil, stirring constantly. Boil, without stirring, 4 minutes or until a candy thermometer registers 240°. Remove from heat; stir in baking soda and vanilla.
Pour sorghum mixture over popcorn mixture, and stir until coated. Divide between 2 lightly greased 15- x 10-inch jelly-roll pans, and spread in a thin layer.
Bake at 250° for 1 hour, stirring every 15 minutes. Cool completely on wire racks (about 45 minutes). Break into pieces.
Note: For a less clumpy texture, stir popcorn constantly for 5 minutes after removing from oven.