Pop 8 C popcorn (preferably in old-school oil popper). Put popcorn in large grocery size brown paper bag.
Heat in a medium saucepan, mix, and boil for 2 minutes:
1/2 C butter or margarine
1 C brown sugar
1/4 C corn syrup (Karo Syrup)
Then add 1/4 tea baking soda and stir. Take pan off heat.
Pour caramel sauce over popcorn in brown bag, fold down bag and shake until popcorn is coated.
Put bag in microwave for 1 minute. Now shake.
Microwave for 45 seconds, then shake. Microwave another 45 seconds and shake.
Spread caramel corn on a baking sheet and let cool.