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

Combine sugar, corn syrup, and vinegar. Heat on medium until low boil stage. Boil to 300 degrees (hard crack stage on candy thermometer). Remove from heat. Add baking soda. Stir immediately. Pour into buttered 9 x 9 inch pan. Cool, break into pieces.