In a medium saucepan over medium heat, combine sugar, golden syrup and vinegar. Cook, stirring, until sugar dissolves. Heat, without stirring, between 149 to 154 degrees C, or until a small amount of syrup dropped into cold water forms hard, brittle threads. Remove from heat and stir in bicarb. Pour into prepared pan; do not spread. Mixture will not fill pan. Allow to cool completely.
In the microwave or over a double boiler, melt chocolate, stirring frequently until smooth. Break cooled honeycomb into bite sized pieces and dip into melted chocolate. Let set on greaseproof paper. Store tightly covered.
Cocoa confectionery coating is available online or in some specialty baking shops. You may get a more 'professional' look with a confectionery coating, however plain chocolate will taste just as nice!
I couldn't believe that my favorite crunchie was so easy to make. Next time though I'll try leaving it to heat to 132 degrees which is actually soft crack. 149-154 is too hard for my liking. - 02 Nov 2010