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Volunteering at Scouts is changing to help us reach more young people

Volunteering is changing to help us reach more young people

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Campfire admirers

Scout out the science of the perfect campfire to create something worthy of the hall of flame.

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You’ll need

  • Firewood
  • Fire lighter (for example, matches or ferro rod)
  • Access to water
  • Wooden skewers
  • Pens or pencils
  • Scrap paper
  • Clipboards
  • Fire buckets with water or sand
  • Cooking utensils, as needed
  • Meal ingredients, as needed
  • Hand wash or soap
  • Marshmallows
  • Biscuits and chocolate (optional)

Before you begin

  • This activity is in three parts and you might want to run it over multiple sessions, on a half-day or during a camp. The first part of this activity involves building fires, so you’ll need somewhere suitable to do this, where you have permission to build fires. The next part involves cooking, so everyone will need to be asked in advance to plan a recipe and share the ingredients and equipment they’ll need. Take the opportunity to ask about food allergies and dietary requirements too. You could use your own recipes, or those from the Go Outdoors ‘Campfire Cookbook.’ Campfire nachos, breakfast burritos, calzone, cabbage burgers and roast chicken are all dishes that’ll work well.
  • Risk assess this activity carefully and use the hints and tips provided by Scout Adventures here.
  • Those working towards their Scouts Scientist Badge should either plan and run their own experiment or use what they learn to share the science with others once they’ve completed the activity. Let them know in advance.
  • You could ask for a STEM Ambassador to help deliver science, technology, engineering and maths (STEM) activities in your programme. Go to the website and register as a ‘youth and community’ group. There, you can share requests for support.

Build your fire

  1. Everyone should split into pairs or small groups and gather everything they think they’ll need for building a fire. This should include a full fire bucket that’s ready to use.
  2. Gather together tinder like small twigs and dried grass, and then some thicker branches and logs. Groups should be careful to only collect dead wood, but they should look out for different types. Pile these by their fire area in order of size.
  3. Everyone should start to build their fire. Each group could use a different structure for a more scientific approach. They should see which shapes and styles produce the biggest/hottest/most resilient blazes.
  1. An adult should check each fire shape is safe and secure, and that each fire bucket is full. Tie up long hair or loose clothing. Now, everyone can light their fire with their chosen method. Make a note of the fire shape, how fast the flame catches, how quickly the wood burns, how long the fire lasts and how big/hot it gets.
  1. Groups could keep their fires going to see how often they need fuelling, how easy they are to control and whether they’re suitable for cooking on. Different wood types could also be burned to see how they compare.
  2. Once everyone has collected all of their information, they should check in with the other groups and see how their fires fared. Discuss which fires were the easiest to light and manage, and how well suited each type of fire was to different purposes, like campfire cooking, keeping warm at night, making smoke signals or illuminating the area. Think about which might be easiest to light in a storm.
  • All fires need heat, fuel and oxygen to survive. Burning, or ‘combustion,’ is a chemical reaction where the fuel breaks up and mixes with the oxygen. This creates water vapour and carbon dioxide (smoke).
  • When starting a fire, the area where most of the reaction takes place is the surface exposed to air. Your tinder and think twigs have a large surface area which exposes it to more air, so it should catch easier when you go to light it. Only once the fire’s going should you start to add larger branches and logs, as these burn more slowly.
  • Different woods burn in different ways. Softwoods are light and will burn quickly, probably too quickly if you’re planning on cooking. Hardwoods burn slower, but for longer, so they’ll eventually generate enough heat to cook. Wet wood will always burn slowly as it needs to use up the heat to dry out first. If it’s too wet, it could put the fire out.
  • Keeping a fire hot relies on more heat being given off by combustion than is lost to the surroundings. Heat may be transferred to surrounding objects and lost. Campfires ‘conduct’ some heat to the ground, but fortunately soil and rocks don’t take away too much. ‘Convection’ is the movement of heat in the form of gas upward from hot fires, but as hot fires draw in lots of oxygen, this shouldn’t reduce heat too much either. Most heat is lost by ‘radiation,’ the transfer of heat to the empty space around your campfire. This happens more the hotter your fire gets. However, you can surround your fire with thermally-reflective materials, like non-combustible stones, which will send back the heat like a mirror.
  • Larger fires in higher enclosures may be needed in poor conditions to reduce heat loss. In a large fire, wood on the outside can enclose the burning wood within, bouncing back the heat and keeping the core toasty. Really big fires will get very hot, so don’t sit too close!


Get cooking!

  1. Now that everyone’s investigated fire structures, it’s time to cook. Everyone should stay in the same groups. Explain to everyone the three kinds of heat transfer described in the ‘Fire factoids’: ‘conduction,’ ‘convection’ and ‘radiation’. Everyone will be cooking using different methods, which involve different kinds of heat transfer that need investigating.
  2. Everyone should take their pre-prepared recipes, ingredients and equipment and decide on the most suitable way to cook each dish. They need to look at the different ways their fire gives off heat, what structure fire they’ll need and what kind of wood they should use. 
  1. Once they’ve settled on these criteria, prepare the fire as before, or use a fire that’s been kept alight and is suitable for cooking.
  1. Prepare and cook the meals. Hands should be washed thoroughly after lighting the fire and before touching food and any food should be prepared in a clean environment. Groups could assign roles, with some people keeping the fire hot and some preparing the meal, to make this easier.
  2. Serve the meal when it’s cooked and dig in. Double-check any meat or fish is well cooked before tasting. While everyone’s eating, think about how well each fire worked as a heat source, what it was like keeping the fire going until the food was ready and if anyone would do anything differently next time.
  • When embers are glowing, this is when they’re giving off the most heat. Keep this going by moving the coals around, feeding on more fuel and shaping a space to cook. Keep combustion going to make up for the heat being lost.
  • Cooking is a heat transfer from fire to food. Using Dutch Ovens or cooking in pouches directly on coals are ‘conduction’ methods. A frying pan over the heat is heated by ‘convection’; the hot air moving upwards. Marshmallows on sticks are toasted by heat ‘radiation’ from the fire.


The perfect marshmallow

  1. Everyone should now use what they’ve learned making fires and cooking dinner on them to toast perfect marshmallows. Start by soaking each wooden skewer in water for about half an hour (submerged, not floating) to be wet enough to not catch fire easily.
  2. While waiting for this, everyone could think about what kind of fire is best for toasting marshmallows. Consider the structures and fuel to use for the best results. Build and light the agreed-upon fire, or reuse a fire that’s been kept alight and is suitable for cooking.
  3. Spear a marshmallow on a wet skewer and carefully hold it close to the hot fire. Think about what happens to the marshmallow as it cooks, how they look, smell and taste, how it’s colour changes. Look out for any that catch fire or drop off the skewer. Think about the methods of cooking used earlier and repeat the process with a second marshmallow, using one of the three kinds of heat transfer to find the best way of cooking the perfect marshmallow (gooey and hot inside, without getting too scorched on the outside).
  1. Everyone should write down what they thought the perfect method was for cooking marshmallows. These should refer to the science of cooking and fire-making. The instructions could be passed on to another group for them to try.
  • Marshmallows should cook best using radiant heat transfer. Getting the marshmallow directly over the fire to use the heat from convection may only be safe on a small fire. Holding the marshmallow against a hot surface to conduct heat will probably cause it to catch fire, drop off or get dirty.
  • Hold the marshmallow a short distance from the fire. It should heat up steadily without burning, and go squishy in the middle. Marshmallows are made of sugar, but more than half their volume is air, causing them to expand when heated. Gelatin-based marshmallow should go gooey, while gelatin-free marshmallow might react differently.
  • As the sugar caramelises, the marshmallow will turn brown. When this happens, the sugar is broken down into smaller molecules that react with each other. This is why cooked marshmallows taste and smell different. Hot fires are perfect for testing this reaction.


A campfire isn’t just for cooking. People have always made fires to ward off predators, keep us warm, illuminate an area and attract attention. Now that we have electric and gas stoves that we can take on camp, why might we still need a campfire? Is it just the novelty of sharing something with the rest of the group, or is it the social aspect of having somewhere communal to sit with your fellow campers? How did it feel working in groups around the fires, performing your roles and combining your skills to complete the tasks?

No-one knew the science of how fires worked when the first humans discovered it, they just had to keep trying and working out how to make the best, most efficient fires by process of elimination. How can knowing the science help us to master this skill a bit quicker than our ancestors? What parts of this activity will you take away to help you the next time you need to whip up a campfire?


All activities must be safely managed. You must complete a thorough risk assessment and take appropriate steps to reduce risk. Use the safety checklist to help you plan and risk assess your activity. Always get approval for the activity, and have suitable supervision and an InTouch process.

Outdoor activities

You must have permission to use the location. Always check the weather forecast, and inform parents and carers of any change in venue.

Heavy and awkward objects

Never lift or move heavy or awkward items alone. Ask for help or, if possible, break them down into smaller parts.


Supervise young people, and only do science activities that are advised and age appropriate for your section. Test activities first, to make sure you’re confident you can lead them safely. Use protective clothing where necessary.


Teach young people how to use cooking equipment safely. Supervise them appropriately throughout. Make sure it’s safe to use and follow manufacturers’ guidelines for use.

Fires and stoves

Make sure anyone using fires and stoves is doing so safely. Check that the equipment and area are suitable and have plenty of ventilation. Follow the gas safety guidance. Have a safe way to extinguish the fire in an emergency.


Remember to check for allergies, eating problems, fasting or dietary requirements and adjust the recipe as needed. Make sure you’ve suitable areas for storing and preparing food and avoid cross contamination of different foods. Take a look at our guidance on food safety and hygiene.

Sharp objects

Teach young people how to use sharp objects safely. Supervise them appropriately throughout. Store all sharp objects securely, out of the reach of young people.

  • Firewood could be bought or collected in advance of the activity, so that there’s enough for everyone. The wood could be damp, for more of a challenge.
  • As well as just making marshmallows, groups could make tasty s’mores. They should see how hot their marshmallow needs to be from the fire to melt the chocolate in the s’more so that it’s just right. Exchange notes and see who made the perfect s’more.
  • If the area in which you find your natural wood is not accessible for everyone, collect or buy wood in advance for this activity.
  • Some fires may need to be built off the ground so that everyone in the group can reach them.
  • Keep on top of everyone’s food allergies and dietary requirements.

All Scout activities should be inclusive and accessible.

There’s some useful bits and pieces in this activity that anyone working towards their Scouts Survival Skills Activity Badge or the Scouts Outdoor Challenge Award could use.

Everyone had the opportunity to show their individual skills as groups completed different tasks that were much easier done together than alone.