Honeycomb. Sea Foam. Sponge Toffee. Cinder Toffee. That-stuff-inside-a-crunchie-bar… the list of names for this stuff goes on and on. But they all mean the same thing. It’s a caramel candy that has been made light, fluffy, and full of holes through the addition of baking soda (sodium bicarbonate). The baking soda adds a slightly salty taste to the caramel, hence the “sea foam” moniker, but the overall taste is caramel.

I grew up loving crunchie bars, and what I then called sea foam. I remember learning how to make it myself and dunking it in chocolate to make my own little bite-size crunchies. It looks complicated, but it’s really not – once you understand it, that is.

All you need (besides the usual things) is a candy/digital thermometer which can get up to 150°C (~300°F) and liquid glucose. Now, you’re local store (if you’re outside the UK) may not sell liquid glucose, but any speciality cooking/baking store should, and even DIY brewery places. If you still can’t find any, substitute white corn syrup, but make sure to evaporate off the water sufficiently. It’s a similar product (both are inverted sugars) but the water content tends to be higher. If you’re unsure what I mean, read on, it’ll make more sense later.

You can find recipes out there for making honeycombs without the glucose, but this recipe is my favourite. I’ve tried a few in the past and found that their candy instructions weren’t always adequate. They often resulted in flat soft honeycomb or burnt-tasting stuff. Which isn’t exactly ideal; I adapted this recipe from my work, until it was perfect. Just stick with me kid 😉

There are three key things for making this work well – patience, temperature, and the right container. For patience – you have to let the solution boil slowly (to evaporate off the water), instead of turning up the heat and rushing it. Candy temperatures are less about the actual temperature, and more about what they represent. Since water boils at 100°C, for a solution to climb above that, it needs to evaporate off water. The higher the temperature, the less water is present (until you hit 100% sugar and caramelization occurs). If you boil too quickly, it may read a certain temperature, but there is still too much water present. So let it boil slowly, and the temperature will climb with the reduction in water.

As for the temperature, you need an accurate thermometer. It’s one of my main faults with a lot of honeycomb recipes out there, as they use colour descriptions instead of temperatures. For honeycomb, you want to get to what is known as the “hard-crack” stage. Anything below that, and your honeycomb will be too soft and chewy, and may even deflate entirely. The hard crack is between 149-154°C. I generally like to get to at least 150, to ensure it’s reached the right stage, but be careful as it’ll climb quickly once it gets past 145ish. Anything above 154°C and you’re in caramelization territory – sounds nice, but too much caramelization ends up tasting burnt. In fact, despite the fact that honeycomb is caramel in colour, we don’t actually caramelize the sugar! It’s the chemical reaction with the baking soda that creates the colour as well as the taste (and sudden increase in size).

For the container – you want to ensure you don’t pick one too big. Having the right-sized container to pour the honeycomb into will ensure it stays nice and tall. I actually used one waaay too big when making this trial batch (see above). I’m used to making this recipe 8x as big, and wasn’t sure how large a pan to use. What ends up happening is that without it reaching the sides, it’ll fall quite a bit and end up sort of flat 🙁 If you put it into a nice-sized container, the sides will support it while it cools, and you’ll end up with tall chunks of light honeycomb. For this amount, I’d recommend a small square pan (like 8×8″), but maybe put some parchment paper underneath in case it overflows a tiny bit.

And that’s it! If you follow those three things (and the recipe below – obviously), you should end up with a great honeycomb! I’ve taught quite a few people to make it in the past, so hopefully you’ll have no issue. Use it to make my No-Churn Honeycomb Ice Cream, coat it in chocolate, or just eat it! Just make sure to store it properly, and quickly. Honeycomb will absorb any moisture present, so if you were to make it on a rainy day, with a window open, you might not have as great success as a drier environment. Once your honeycomb is hard, break it up and store it in an airtight container. I worked at a restaurant where we would vacuum-seal little bags of it so that we only had to open a small amount during service. Just don’t let it sit around in the kitchen too long after you make it, or it’ll get all sticky. (Like cotton candy! That stuff practically melts if left outside…)

It’s such a fun thing to make – the baking soda creates such an instant reaction (which is why I have no photos of it). It’s a fun thing to do with older kids, as long as they are careful. It’s like a science experiment you can eat! Yum!

Homemade Honeycomb


  • 134 g sugar
  • 25 g honey
  • 47 g glucose white corn syrup
  • 16 g water
  • 10 g sodium bicarbonate baking soda


  • In a small pot over medium heat, use a whisk to combine all ingredients except for the bicarbonate*
  • Bring to a boil, and dissolve the sugar, whisking occassionally
  • Continue boiling, evaporating off the water, adjusting the heat so that it doesn’t boil too rapidly
  • While the mixture is boiling, sift the bicarbonate in a small bowl, and prep a small baking tray by completely lining it with parchment paper
  • Once the sugar solution reaches 150°C (302°F), remove from the heat and quickly whisk in the bicarbonate. Make sure you whisk enough that you aren’t left with pockets of baking soda, but not too long or you’ll deflate it
  • Immediately pour the honeycomb into your prepared pan, being gentle so as not to deflate the mixture. Don’t be tempted to touch the surface while scraping in the last bits, or you’ll end up deflating it
  • Allow to cool (the surface will be hard) then break into small pieces and store in an airtight container


*make sure the pot isn’t too small, as the baking soda reaction grows a lot!

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