There’s something magical about gooey marshmallows and melted chocolate tucked between two crunchy graham crackers. We love a good s’more—but let’s be honest, setting up a campfire during the day isn’t always quick or convenient.
Enter: the solar s’mores oven!
This kid-friendly science + snack activity uses the power of the sun to cook your favorite campfire treat—and gives your little learners a taste of solar energy in action.
Supplies
- 1 pizza box (or other cardboard box with a lid)
- Aluminum foil
- Stick or dowel to prop the lid
- Clear plastic wrap or a sheet protector
- Black construction paper
- Tape and/or glue stick
- Scissors or box cutter (grown-up use only)
- S’mores ingredients: graham crackers, chocolate squares, marshmallows
How to Make Your Solar Oven:
- Cut a flap in the lid of the pizza box, leaving a 1-inch border around three sides. Lift it up gently like a flap.
- Line the underside of the flap with aluminum foil (shiny side out). Tape it in place—this will reflect sunlight into the box.
- Cover the opening in the lid with clear plastic wrap to trap the warm air inside, like a greenhouse. Tape it tightly so there are no gaps.
- Line the bottom of the box with black construction paper. This absorbs the sun’s heat and helps cook the s’mores faster.
- Assemble your s’mores: Place a graham cracker square, a piece of chocolate, and a marshmallow in the box. You can top it with the second cracker later!
- Close the lid, angle the foil flap to reflect sunlight into the box, and use a stick or ruler to prop it open.
- Set your oven in the sun, and wait patiently! After 30–60 minutes (depending on temperature and sun strength), the chocolate will melt and the marshmallow will get warm and gooey.
What Kids Learn:
This is more than just a tasty treat—it’s a mini science lesson! Here’s what your kids are exploring:
- Solar energy and how it can be harnessed to heat things
- Insulation and the greenhouse effect
- The role of reflection and absorption in creating heat
Encourage them to make predictions, observe changes over time, and compare how long it takes different foods to heat up!
Tips for Success:
- Do this on a hot, sunny day (midday sun works best!)
- Angle the foil flap to reflect the most sunlight into the plastic-covered opening.
- Try melting two s’mores—one in the solar oven, one outside of it—and compare!
Conversation Starters:
- “Why do you think we used black paper instead of white?”
- “What would happen if we didn’t use plastic wrap?”
- “Do you think we could cook other things this way?”
Extend the Fun:
- Try heating other treats like mini pizzas, nachos, or chocolate chip cookies!
- Make it a challenge—who can build the most effective solar oven?
- Pair it with a book about the sun or renewable energy for a science connection.
Final Thoughts:
This solar s’mores oven is one of our favorite summer activities because it checks all the boxes: delicious, educational, hands-on, and zero flames required. Whether you’re camping in your backyard or just soaking up some sun, this is a sweet way to explore science together.
Give it a try—and let the sunshine (and marshmallows) melt your hearts!
More fun science here: salt art!
