DIY Solar-Powered Smores!

Get Ready for S’More Summer Science!

Combine Learning Resources’ Summer of Science and National S’mores Day and what do you get? Simple instructions for creating your very own backyard solar oven to bake, what else, s’mores! This educational (and delicious!) project combines crafting, science, and sweets – the perfect recipe for summer fun. What are we waiting for? Let’s get started!

What You’ll Need:

• A sunny day (the hotter, the better)
• Any size pizza box (if you don’t have one in the recycling can, ask your local pizzeria – ours gave us two clean boxes for free, in the name of science)
• Tin foil
• Plastic wrap
• Black construction paper
• Tape
• Scissors
• Chocolate bars
• Graham crackers
• Marshmallows
• Paints or markers

What You’ll Do:

Complete the following steps inside to avoid melting chocolate (and a sweaty back):

Have your kids use the paints and markers to decorate the outside of your box.

Cut a large square out of the top of the pizza box. This will be your solar oven’s “door”. (This is a grown-up job.)

Show your kiddo how to trace around the bottom of the pizza box onto a sheet of black construction paper, then cut just inside the traced lines to create a slightly smaller square and place it inside the box. This will make a heat-absorbing base for your oven (more on this below).

Tear a sheet of tin foil large enough to cover the inside of your oven’s door and fold it over the door to keep it into place (or tape, if you like).

Lift the lid out of the box and, keeping the “oven door” separate, carefully wrap a sheet of plastic wrap around the opening, taping it securely on all sides.

Place your s’mores inside your oven, beginning with a graham cracker, then chocolate, then marshmallow. Leave the graham cracker “lid” off for now to allow for better baking.

Close the plastic-wrapped lid over the s’mores.

Head outside and position your box on the ground (away from any ants or bugs) so that the sun is hitting the reflective “oven door” – use tape or a pencil or skewer to prop the door open, if necessary, or prop something behind the door if wind is blowing it backward.

Wait and watch. The chocolate will likely melt right away, but, depending on the outside temperature, it could take anywhere between 90 minutes and 3 hours for your solar s’more marshmallows to get “smooshy”.

When they do, remove the plastic wrap from the oven and enjoy your solar-powered sweet treat!

How It Works:

Sneak some science into this backyard buffet by explaining how your solar oven works. Explain to your science smarties that they could set their s’mores on the concrete on a hot day and eventually they would melt, because the sun is giving off heat – we can feel it on our faces and our backs. But the solar oven will do the work a whole lot faster. Why?

Well, first, the tin foil is reflective, meaning it absorbs the sun’s heat and reflects it back in a specific direction – in our case, onto our s’mores.

And, because it is black, our construction paper layer is absorbing light and converting it into heat, helping to melt our s’mores from the bottom. Black absorbs all wavelengths of light – in contrast, white does not absorb any wavelengths, so makes no heat.

While you’re waiting for your s’mores to melt you might demonstrate this concept by having your kids sit in the sun for a few minutes in a white t-shirt and then change into a black one and sit a while longer. They’ll definitely feel the difference.

Together, the tin foil, black paper, and plastic wrap create the perfect “oven” to melt our s’mores. Mmm, mmm!