Friday, October 22, 2010

Sunny cookies

Yesterday I was reminded of how cool my job is and just how fortunate I am to work in such a facility where experimenting is part of the job and mess-ups are usually still eaten. You see recently we acquired a very nice sized box that had served as a shipping cooler space so it was already conveniently lined with reflecting insulation. As soon as I saw it I knew that it could serve as another useful item. I could either make a Halloween costume out of it, maybe be a microwave, or I could make it into a sun/solar oven. How convenient that I work in the bake lab and we happen to have items on hand to experiment with on a normal basis. I opted to go with the second option. 

This would be my box with conveniently insulated sides. They were already lined with a reflector sheet so I simply had to fill in the gaps with some aluminum foil. I also covered the top with plastic wrap to create the oven box. I stuck a black t-shirt in the bottom of the box to attract the heat and put a simply cake pan down there with my three cookies. I covered the pan of cookies just as another way to trap additional heat. A few books under the box tilt it toward the sun.

See my cookies down in there? By now, after only about 10 minutes in the box I have already realized a few flaws. The cookies are sliding down the pan. Duh. The pan on the bottom should be level so I don't end up with a blob of cookie dough on the bottom of the slope. After about another 30 minutes I realize that it's simply too windy and my box doesn't weigh enough as it blows over and my cookies are now definitely in a blob on one side of the pan. After I rearrange my box and pan and now weight inside the box a few too many times I realize that the plastic wrap on top keeping the heat in is simply not going to cut it. I need an actual piece of clear plastic or glass, something a little more substantial for a proper seal and heat trapper. I think I had to move the box about 5 times during the course of the 4 hours it took to half bake a cookie due to the rapidly moving sun and the location I chose. 

At about 3:30pm I realize there is not enough sun left in the sky to do anything more for my baking action so I  abandon oven action. My cookies look fairly normal, still kinda a blob. Because it is late October and the sun is so low in the sky only about half of the cookie pan was actually in direct sunlight. Another thing I learned was my box was too deep to allow proper sun and it was simply too much space to heat up. A lot of wasted space is unnecessary. It did manage to get up to 218 degrees in there at one point. I believe a properly designed sun oven should get to normal baking temps though.

Mmm. Grandma's Old Fashioned Molasses cookies, my favorite. Not sure if you can tell but half the pan, the part in the direct sun was definitely done and crunchy. The other half that never made it into the direct sun was a little under baked and doughy. Good thing experimenting is encouraged in my workplace and even the rejects get eaten by bake lab participants!


  1. What a fun experiment! You learned so much from this experience, that I'm sure you'll be able to bake wonderful cookies this way next summer should you try again.

  2. Your design is pretty great though! I remember the ovens at the fair having a glass (or maybe fiberglass) box in the bottom. But you already figured out that was the missing link, you're so smart! :)

  3. Good for you, Panda! I've always wanted to make a solar oven, and will surely learn from your mistakes. Keep up the experimentation, my friend!

  4. Fantastic experiment Amanda! Do science to things!