Place the water, honey, glucose and sugar into a large saucepan.
Line the base and sides of a 23 x 28cm deep baking tray with baking paper. Generously spray the paper with cooking oil.
Heat the honey mixture in the saucepan over medium heat, whisking frequently.
Cook the syrup until it reaches 152 °C. At the point turn the heat off, remove the thermometer and give the syrup a good whisk.
Whisk the bicarbonate of soda into the sugar syrup well. At the point the mixture will expand rapidly. Please be careful here as the sugar mixture is extremely hot.
Lift the pan and carefully pour the honeycomb into the prepared tray, using the whisk to scoop out any remaining honeycomb.
Leave the honeycomb for at least 2 hours to cool. Once cool, remove from the tin and break into pieces to serve.