6 qts. popped popcorn
2 c. light brown sugar, firmly packed
1/2 c. light corn syrup
1/2 lb. butter
1/4 tsp. cream of tartar
1 tsp. salt
1 tsp. baking soda

Preheat oven to 250 degrees. Place popcorn in large 4" deep buttered baking pan. Keep warm in oven. In a large saucepan combine brown sugar, corn syrup, butter, cream of tartar and salt. Bring to a boil over medium high heat, stirring constantly. Continue to stir and boil rapidly until hard ball stage, 260 degrees. (Hard ball stage, when a drop of candy is dropped in glass of cold water and it does not stick to side of a glass.) Remove from heat, stir in baking soda. Pour syrup over popcorn and stir. Bake at 200 degrees for 1 hour. Stir during baking. Let cool. Break apart. Store in tightly covered container.