Baking with the Solarofen
Published: June 28, 2009
A few years ago, Waldsee took a giant leap in the direction of sustainability with the construction of the Biohaus. The Biohaus is a certified passive house, which means it has extremely efficient insulation and maximizes the energy available from the sun for heating. The Biohaus is home to campers, staff, and a wide variety of educational science and nature exploration kits. One of the kits is a Solarofen (solar oven), which uses heat from sunlight to bake the food inside. Last Thursday, Vera and I took our Gesprächsgruppe (discussion group) to make two pans of mango banana bread in the Solarofen. We first talked about the basics of cooking and baking and then introduced the names of the Zutaten (ingredients) for our bread. We laughed as one of us mashed the mangos and bananas into a sloppy mush, and we all took turns mixing the ingredients together to create the Teig (dough). We then put the Teig into the pans, the pans in the oven, and the Solarofen in the sun. The recipe said that the bread would be ready in about 1.5 hours, but my experience with traditional baking told me that it would likely take at least 2 hours. We also put the oven in the sun at 3pm, which was another reason to over estimate the time needed to bake. Baking with the Solarofen is a risk in terms of being able to check and see if the food is finished baking. The inside of the oven is completely black, with an insulated body, and an insulated plastic window cover that lets sunlight in and traps the heat inside. There is also an additional reflective trim that directs more sunlight into the oven. Yet, once one removes the insulated window, all the trapped heat escapes and baking comes to a halt. If one does this and the food is not done, then it will take an even greater amount of time to bake because the oven has to heat up again. So we did not check on the bread until 5:30pm, 2.5 hours later. The temperature inside the oven climbed to about 260 degrees Fahrenheit, and the bread cooked at this temperature for probably 1.5- 2 hours. Even if we did over estimate the time, we did not have to worry too much about burning the bread because at this temperature the Solarofen bakes slowly. After the first hour and a half, I noticed water collecting on the inside of the insulated window, which meant the water was cooking out of the bread. I also turned the oven too so that it would point directly into the afternoon sun. After 2.5 hours we carried the Solarofen into the Gasthof (dining hall). The outside was cool to the touch, but we were careful because we knew the inside was still very hot. We caught a whiff of the bread as we carried it and it smelled great! We set the oven down and carefully took off the insulated window. Steam and heat shot out as we took the cover off to retrieve what sat inside. The pans were very hot, so after they cooled down, we looked inside an saw two wonderful looking cakes. The recipe was more cake like than bread, but everyone was excited to try a piece. All in all it was a great experience because the kids had lots of fun learning about baking and the use of solar energy. I would like to try other recipes with the solar oven and even try to bake an entire meal.