Combine honey, golden syrup, caster sugar, cream of tartar, and water in a large saucepan.
Cook over low heat for 5 minutes to dissolve the sugar.
Slowly increase the heat to bring it to a boil. Cook for 6-7 minutes, without stirring, until the syrup starts to crack at (150°C) on a sugar thermometer or turns golden brown.
Remove from heat immediately and use a wooden spoon to stir in the bicarbonate of soda quickly until you see bubbles and foam. Let it cool for an hour, and then enjoy!