How to Make the Perfect Cinder Toffee

Do you use butter and honey or keep it simple with sugar? Is there anything finer to eat around the bonfire, and do you make any other recipes that are more akin to a science experiment?Cinder toffee (also known as hokey pokey, puff candy or even sea foam, depending on where you are in the world) is best described, to the uninitiated, as "that stuff you get inside a Crunchie bar". It is brittle yet sticky, with an airy, honeycomb-like texture that makes it well-nigh impossible not to eat one piece too many, and an addictive slightly bitter edge, thanks to the caramelised sugar and the bicarbonate of soda that creates all the holes. Along with the similarly bitter but rather chewier treacle variety, and the smothered-apple sort, cinder toffee is a popular choice for those commemorating the grisly downfall of Mr Guy Fawkes (or, at least, enjoying some fireworks and an almighty bonfire) on 5 November. It is certainly one of the most fun things you can make in the kitchen, more akin to a chemistry experiment than a recipe, but with rather more delicious results than even the infamous exploding custard tin. But what's the best way to make it?Sugars

Let's face it, this is not a dish for anyone who's sworn off sugar in recent months - the "healthiest" variety I find is Martha Stewart's recipe using honey, but even that is in a ratio of 1:6 in the refined sugar's favour. Other versions add golden syrup, with Miss Hope and Mr Greenwood's Sweets Made Simple going for the triple with sugar, golden syrup and glucose syrup for good measure. I really like the flavour of the honey, but the resulting sweet doesn't taste like cinder toffee to me - call it honeycomb, and I'm in. Glucose syrup, conversely, seems a bit one-dimensional. Golden syrup is a good compromise: subtler than the honey, but with a more interesting, caramelised sweetness than the white glucose. The colour and texture of the sugar is also up for debate: Hope and Greenwood use ordinary granulated, Nigella Lawson goes for caster and Gary Rhodes opts for demerara (which is, of course, granulated as well as brown) on top of caster. Caster melts more quickly (though I'll be ignoring Lawson's advice and stirring the pan before it comes to the boil - the sugar takes ages to melt otherwise), but Rhodes's brown sugar has a richer flavour so, like him, I'll be using both.Liquids

Lawson's recipe is the simplest: just sugar, syrup and bicarbonate of soda for that all-important burst of carbon dioxide. Hope and Greenwood, Rhodes and Mrs M Cunning of Ballintoy WI, as featured in the Federation of Women's Institutes of Northern Ireland Cookbook (a source I tap into through the kindness of strangers on social media) all add water in varying amounts, while Christine Grimshaw pops in a little vinegartoo. The less water the better when it comes to a hard candy, but a splash does make it easier to melt the sugar without it burning. The vinegar, however, seems a bit pointless - I assume the idea is that it will react with the bicarb to produce larger bubbles, but in fact, Grimshaw's falls relatively flat.Fat

Most cinder toffee recipes are a fat-free zone (which is not to say that they're in any sense a health food), but Cunning and Grimshaw both add butter to theirs, as you might to a more traditional chewy toffee. Though the versions that use butter are less voluminous than their strictly sugary counterparts, they have a gorgeously rich flavour the straighter kind can't compete with. So much for a fat-free treat.Bicarbonate of soda

This is mixed into the molten sugar mixture, the heat of which breaks down the bicarbonate of soda, releasing carbon dioxide and creating a rather startling bubbling beige lava field in your saucepan. Though you have to work quickly before the sugar cools, it's also vital that you whisk it in thoroughly, or you'll come across bitter, salty pockets in the finished confectionery. Hope and Greenwood add the most, with 15g to a mere 200g sugar, while Cunning uses the least: only one small teaspoon for 600g sugar. This may explain why the Hope and Greenwood toffee is a towering, terrifying honey-coloured mass with impressive honeycombing but a distinct flavour of bicarb, while Cunning's is only marginally airier than a brittle pancake. Stewart's has the best texture; light, but with a satisfying crunch to it.Temperature

The higher the temperature to which you heat the sugar, the harder the end result. Lawson's recipe, which cooks it for a mere three minutes to Hope and Greenwood's 15, is sticky and chewy (and has the smallest holes of all the versions I try). Most recipes suggest you take it to hard crack stage, or about 138-140C (280-284F), though Stewart goes even higher, to 150C, and Hope and Greenwood rely on the rather vague instruction to cook it until it's the colour of marmalade. Cunning prefers the old cold water test, directing the cook to drop a little in "to see if crisp", but this is quite stressful - sugar thermometers aren't expensive, and they do make life a lot easier in this case. To my surprise, 150C seems to work quite well, but the risk of burning the sugar is far higher - I'd advise playing it safe with 138C. Last piece of advice: make sure you grease the tin diligently. If you line it, you risk the prospect of picking pieces of greaseproof paper from your teeth for the next fortnight. It should come out easily if you're free enough with the butter.

(Makes more than you can eat)165g demerara sugar165g caster sugar60ml golden syrup4 tbsp water15g butter, diced, plus extra to greasePinch of salt1 tbsp bicarbonate of soda Put the sugars, syrup, water and butter in a deep, heavy-bottomed pan with a pinch of salt. Heat gently, stirring, until the sugars and butter have dissolved, then turn up the heat very slightly and bring to the boil. Simmer until it reaches 138C and is bubbling and amber (this will take about 10-15 minutes). Meanwhile, generously grease an approximately 24cm square tin. Put the bicarbonate of soda by the hob. When the mixture gets to temperature, take it off the heat and quickly whisk in the bicarb, making sure it is well mixed in. Pour into the tin and leave to set. After about 15 minutes, you can score it into pieces if you like and leave it to set completely. I prefer to wait, then smash it into shards with a heavy object once solid. Cinder toffee, honeycomb, puff candy: what do you call it, and what are your sweetest memories of scoffing it? Butter or no butter, honey or syrup - and is it the best thing to munch around the bonfire?
Felicity Cloake's perfect cinder toffee. Photograph: Felicity Cloake/Guardian