8 c. popped corn (about 1/2 c. unpopped)
3/4 c. granulated sugar
3/4 c. brown sugar, packed
1/2 c. light corn syrup
1/2 c. water
1 tsp. white vinegar
1/4 tsp. salt
3/4 c. butter

Measure popped corn into large bowl. Combine sugar, corn syrup, water, vinegar and salt in 2-quart saucepan. Heat to boiling over medium-high heat, stirring frequently. Cook, stirring constantly, to 250 degrees on candy thermometer (or until small amount of mixture dropped into very cold water forms a hard ball). Reduce heat to low; stir in butter until melted. Pour syrup in thin stream over corn in bowl, stirring until corn is well coated. Cool slightly. Butter hands and shape mixture into 3" balls and place on waxed paper.