Caramel Popcorn Balls

Measure popped corn into large bowl. Combine sugars,corn syrup, water, vinegar, and salt in 2 quart saucepan. Heat to boiling over med. high heat, stirring frequently. Cook, stirrng constantly, to 260' 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; shape mixture into balls and place on waxed paper.