1 c. sugar
1 c. dark corn syrup
1 tbsp. vinegar
1 tbsp. baking soda

Combine sugar, corn syrup, and vinegar in a heavy saucepan. Cook over medium heat, stirring until sugar is dissolved. Continue cooking, without stirring, to 300 degrees on candy thermometer (or until a little of the mixture dipped in cold water becomes very brittle). Remove candy from heat. Gradually stir in soda. Mix well. Pour into a lightly buttered 9 x 9 x 2 inch pan. Do not spread (will spread itself). Cool and break into pieces. Makes 1 pound. If desired, you can dip pieces in melted chocolate and drop onto wax paper. (Mixture will foam when soda is added, use a large pan.)