Blow Something Up

Gastronaught_Choc factory_0547 (3)


‘I have developed a solution: blow something up.’  


Kids love being lectured about nutrition. They think the EatWell plate is really cool, (especially those colourful illustrations), they are fascinated by calories and they adore learning the principles of a balanced diet. Oh, and they really love learning why they shouldn’t eat sugary food and drink.

No they don’t. They hate you for it. They hate you for telling them that the foods they love are bad, they pity you for wagging your finger at their lifestyles and they particularly hate you for boring them with theoretical, unvisualisable negativity about sugar.

But despite everything, you and I really want those stinky little beasts to eat better food, live healthier lives and feel happier inside. So what are we going to do? Throw a dab? Tell them that vegetables are peng? Don’t even go there.

Stefan 1

I’ve been talking to kids about nutrition for years – on TV, in books and on stage – and whenever I resort to telling them what I want them to think, they’ve always been able to see through my bullsh*t from a mile away. Sure, they’ll sit and listen, and sometimes they’ll even be able to repeat some of my lazy facts back to me, but I don’t think it makes a blind bit of difference to how they think or eat in the long run. We have to work so much harder if we want them to care, so we have to show, not tell. I have developed a solution: blow something up. It’s not going to change kids’ diets straight away (I truly believe that nothing will), but it leads them to a fascination with food and nutrition that that no lesson can achieve. So here’s how to do it without burning the house down.

This is essentially two simple science demos:

  1. Where does sugar come from?
  2. How to make a flamethrower using sugar. This is a journey of discovery – don’t tell the kids what the powder is – first get them to blow some up (under tight supervision) and then get them to guess what it is and then eat some, BEFORE revealing what it is.

I’d urge you to try this out with some kids – but you will obviously need to write a thorough risk assessment as it can be dangerous. I’d love to hear if you think it’s useful, workable or pointless.

You’ll need:

  1. OPTIONAL demo (optional because you need to find some sugar cane)


  1. Optional: 20cm piece of sugar cane (available from many Bangaldeshi food shops)
  2. Optional: Mallet
  3. Optional: chopping board


  1. Main demo:


Stefan 2

  1. 2 x pairs safety goggles
  2. 3 tsp Icing Sugar (also Bird’s Custard powder/Coffee Mate milk powder will do) store them in a container with no label
  3. 50cm garden hose
  4. Empty plastic drinks bottle: Cut the top off the drinks bottle to give you a simple funnel. Attach the bottle top end to the hose so that it’s now a very long funnel, and tape it up with electrical tape or similar (do this in advance)
  5. Electrical tape or gaffer tape
  6. Gas blowtorch
  7. Lighter
  8. Optional: lab stand with arm and boss head
  9. Clear plastic cup
  10. Teaspoon
  11. Drinking water



  1. OPTIONAL demo (optional because you need to find some sugar cane)


  1. Ask for a volunteer – one that has no food allergies/intolerances
  2. Ensure both you and volunteer are wearing safety goggles
  3. Show audience a piece of sugar cane and ask them to guess what it is. If they can’t guess, tell them.
  4. Place sugar cane on a chopping board and get volunteer to whack it with a hammer until it breaks apart and you can pull a piece off. Both you and volunteer should crush a piece in your teeth and suck it. Ask what it tastes like: it tastes sweet. Half our table sugar in the UK comes from cane (the other half comes from sugar beet).


  1. Main demo:


  1. Ask for another volunteer – one that has no food allergies/intolerances
  2. You and volunteer must now put on eye protection. Gloves are not necessary. Have a fire extinguisher standing by and make sure that smoke alarms are turned off.
  3. Place your blowtorch on a lab stand or solid surface with at least 3m clearance height above it and no flammable materials above.
  4. Ask the volunteer to hold the long funnel in a U shape, with the wide funnel end pointing up and the other small end also pointing up. Place 2-3 teaspoons of your icing sugar into the funnel, and then position the volunteer so that they can blow into the hose. The idea is for the volunteer to blow the powder out across the blowtorch flame, pointing away from you and the volunteer, and upwards. This will ignite and the chemical energy in the carbohydrate powder will change into heat and light. It will create a fireball about 1-1.5m wide and 1-3m long.
  5. Turn off the blowtorch.
  6. Ask the volunteer to put a teaspoon of the ‘explosive powder’ into a clear cup, then add water. Get them to taste it and ask what it tastes like. They may refuse to drink as it’s ‘explosive powder’. If so, offer to drink some with them.
  7. When they have tasted it, you can reveal that it is icing sugar and that the flame they saw was about 20-30Kcal of simple carbs being burnt. Compare that with a Mars Bar, but DON’T be negative about it!
  8. Warn them not to try this without an adult.


Good luck,



Stefan Gates describes himself as a ‘food adventurer’ and really enjoys blowing stuff up. He has written and presented 16 TV series including food science series Harvest (BBC2), Food Factory (BBC1) and E Numbers: An Edible Adventure (BBC2), and three series of Cooking in the Danger Zone (BBC2) about global hunger and the politics of food. He also makes the acclaimed kids’ series Incredible Edibles and Gastronuts (CBBC). He appears as a guest on dozens of others from Newsnight to Blue Peter, and is a regular panelist on Radio 4’s Kitchen Cabinet. He has recently finished two BBC4 documentaries: Can Eating Insects Save the World? and Calves Heads and Coffee: the Golden Age of English Food. He has written several books including Incredible Edibles and The Extraordinary Cookbook.