Start out with 16 c. popped popcorn
1 stick butter
1 c. brown sugar
1/4 c. Karo syrup

Cook for 2 minutes on high in microwave. Stir, then boil for 3 minutes on high in microwave. Mix in 1/4 teaspoon baking soda. Pour over popcorn and toss gently. Cook for 3 1/2 minutes on high, stopping every 30 seconds to toss. Spread out on wax paper to cool. Store in dry place.