2 batches of popcorn (approximately 15 c.)
1 1/2 c. packed brown sugar
1 1/2 cubes butter
Scant 1/2 c. light corn syrup
3/4 tsp. salt
3/4 tsp. baking soda

Grease two 9 x 13 inch Pyrex dishes with butter. Put 1/2 popcorn into each dish. Heat oven to 200 degrees. Mix brown sugar, corn syrup, butter and salt. Melt in saucepan. Cook and stir over medium heat until it bubbles around the edges. Cook 5 more minutes. Stir in baking soda until foamy all over. Pour 1/2 sauce over each dish of popcorn. Stir well until evenly covered. Bake 1 hour stirring every 15 minutes. Store in plastic bags.