I'm struggling with a honeycomb (I think you guys in America call it sponge toffee?) recipe at work. Our spec is 400g sugar, 40g honey, 500ml water and half a tablespoon bicarb. I can get close to the result I am trying to achieve, but it's extremely inconsistent. The basic process I'm using is:
1. Combine sugar, water and honey in a stainless steel pan
2. Heat to around 155 centigrade (by eye!)
3. Whisk in half a tablespoon of bicarb
4. Pour into metal tray lined with baking paper
Guessing the temperature by eye is proving extremely difficult, I think I may have to invest in a sugar thermometer. However I've noticed that usually the sugar mix seems to be overcooked in some parts of the pan and under in others. This also comes out in the final honeycomb as a kind of swirled light/dark pattern. I'm using the heaviest-bottomed pan available, and obviously cannot stir the mix. Any suggestions?
Also, the honeycomb tends to sink in the metal tray. I've got a feeling this is too much bicarb, causing the mix to rise too much, to the point it is unable to support it's own weight - breaking it open reveals large oval shaped squashed bubbles. However, I made one the other day with hardly any bicarb - the bubbles were tiny - yet it still sunk.
It seems like there are so many variables to control in this recipe, and it's proving almost impossible to figure out which ones are affecting the final result.
Any other general tips/suggestions much welcomed!