Few things are more essential to a summer camping trip than marshmallows, chocolate and graham crackers. Sure, you need a tent and a sleeping bag, but a campfire without s’mores just wouldn’t be the same. Fortunately you don’t have to plan a camping trip to enjoy these gooey treats. In fact, you don’t even need a campfire. With a few recycled materials you can construct a solar oven to whip up s’mores anytime of the year. You can always pitch a tent in your backyard if you want a more authentic camping experience.
• Pizza box
• Aluminum foil
• Black construction paper
• Clear plastic wrap
• Pencil or pen
• Sheet of notebook paper
• Wooden dowel or stick
• Paper plate or pie tin
• Graham crackers
1.) Close the box and lay a piece of notebook paper in the center of the lid. Trace the paper with a pen or pencil.
2.) Set the piece of paper aside.
3.) Carefully cut along three lines of the rectangle that you drew on the box. Be careful not to cut along all four lines. You want to leave one side uncut so that you can fold the cardboard up to create a flap.
4.) Use glue or tape to cover the inside of the flap with aluminum foil. Smooth out as many wrinkles as possible.
5.) Cut a piece of plastic wrap that is slightly larger than the open square on the top of the pizza box. Stretch the plastic wrap across the opening and tape it down on all four sides to form a good seal.
6.) Open the box and cover the bottom and sides with aluminum foil. You can use glue or tape to attach the foil to the inside of the box.
7.) Place a piece of black construction paper on top of the foil in the bottom of the box and tape it in place.
8.) Put a paper plate or pie tin containing your s’more ingredients in the center of the black paper.
9.) Carefully close the box top and use a dowel or stick to prop open the flap.
10.) You are now ready to start cooking. Take the oven outside and put it in a sunny location. Turn the box so that the foil-covered flap is facing the sun. You might need to adjust the placement of the dowel so that the sunlight is reflected off of the flap and into the box.
11.) Check on your cooker every 15 minutes until your s’more is ready to eat.
Now Try This:
See if you can speed up the cooking time by adding insulation to your cooker. Try placing wads of newspaper or aluminum foil along the inside of the box. Experiment with different materials until you figure out what works best.
What’s Going On?
Your solar cooker works by converting sunlight into heat energy and then trapping the heat inside the box. This is similar to a car that has been sitting in the sun all day. When sunlight hits an object, one of three things can happen. The light can pass through the object, it can be absorbed by the object or it can be reflected by the object. In your cooker, the light is reflected off of the shiny surface of the aluminum foil and then passes through the clear plastic wrap. The light is absorbed by the black construction paper, which causes the paper and the air inside the box to heat up. Over time, the temperature in the box gets hot enough to melt marshmallows and chocolate.
Debbie DeRoma is the education manager at the Reuben H. Fleet Science Center.