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

Combine first three ingredients. Cook over medium heat, stir only until sugar dissolves. Cook to 300 degrees (hard crack stage). Remove from heat and quickly add baking soda. Use deep pan for cooking, since soda will cause mixture to double in bulk. Pour into a buttered 9 x 9 inch pan, do not disturb, stir only slightly.