Old-Time Popcorn Balls
["5 qt. unsalted popped corn", "1 1/2 c. water", "1/2 c. light corn syrup", "1 tsp. vanilla", "2 c. sugar", "1/2 tsp. salt", "1 tsp. vinegar"]
["Keep popcorn hot and crisp in slow oven.", "Butter sides of saucepan.", "Combine remaining ingredients except vanilla.", "Cook to hard ball stage (250\u00b0).", "Add vanilla.", "Pour slowly over hot popped corn, stirring just to mix thoroughly.", "Butter hands lightly; shape into balls.", "Makes 15 to 20."]
["corn", "water", "light corn syrup", "vanilla", "sugar", "salt", "vinegar"]