Line a baking sheet with parchment paper and set it aside.
In a medium saucepan, combine the sugar, corn syrup, and water. Stir gently over medium heat until the sugar dissolves completely.
Once the sugar has dissolved, stop stirring and let the mixture come to a boil. Continue boiling until it reaches 300°F on a candy thermometer, about 5-7 minutes.
Remove the saucepan from the heat and quickly whisk in the baking soda.
Immediately pour the foamy mixture onto the prepared baking sheet. Allow the honeycomb to cool completely at room temperature, about 30 minutes.
Once cooled, break it into irregular pieces by hand or with a knife.