Out in the wilderness with nothing but a lemon, copper clips, zinc nails, wire, and some steel wool? Then you’re in luck, because those are the only things you need to start a campfire, as demonstrated in the video above by Swedish-based YouTuber NorthSurvival. The project is a quick lesson in electrochemical reactions and circuitry. 

To understand why this works, it’s helpful to understand how batteries generate electricity. According to Scientific American, batteries are “containers for chemical energy.” When two electrodes (each a different kind of metal) are placed in a liquid electrolyte and connected by a conductive material, they generate electricity. Lemon juice is a good electrolyte, which makes the tangy fruit a perfect fire starter. In the video (above), NorthSurvival sticks his electrodes (zinc nails and copper clips) into the lemon and connects them in series (positive to negative) to one another, leaving the ends free for wires. Touching the exposed wire leads together in the steel wool completes the circuit and causes sparks, which NorthSurvival uses to ignite the toilet paper into a small fire.

It’s fair to say that most people that find themselves in the wilderness won’t have access to fresh lemons and may not have zinc nails and copper plugs handy, but this is still a smart trick to know. Learn it by watching the clip above, and subscribe to NorthSurvival’s channel for more lessons. 

Banner image via YouTube

[h/t Gizmodo]