It’s a little over 2 weeks before departure…and I have yet to successfully make yogurt outside of my kitchen. I’m getting closer, but also more desperate. I have a fourth experiment (no yogurt, just a temperature maintenance test) on my kitchen counter now – I’ll report back tomorrow on its success. (It’s in a 30-year-old thermos rescued from the floor of Blackstone Bikes…so I have my doubts, but we’ll see.)
Experiment number 2 was a slight upgrade from sun experiment 1, which almost worked. For this one, I simply stuck my yogurt jar in a black garbage bag, hoping to capture some of the sun’s heat and store it a little longer and hotter. I sat it on the roof of Experimental Station all day long, on a consistently hot day.
At the end of the day…I had my first MISERABLE complete yogurt-making failure I can remember. I was holding a hot jar of cream. It smelled sweet and creamy and sour all at the same time. I tossed it right down the drain.
Experiment number 3 was much more involved. I did some research on some awesome websites about solar ovens (I really want to make one out of an umbrella, but I don’t need to grill my yogurt, so it didn’t seem appropriate), and made one of my own.
I was excited, but also a little skeptical. Espeically of the hinge, which was screwed weakly into styrofoam. My worries turned out to be justified, because the top broke off the in wind on the way to Experimental Station. No reflectors for me! (I had intended to use the foil-covered roof as a reflector in the middle of the day and then close it as the sun sunk lower and cooler during the afternoon.)
In any case, this experiment definitely made yogurt, just really, really watery yogurt. I had my thermometer stuck in the top, in the shade, for the whole day, and checked it periodically. The temperature was fluctuating a LOT, so that likely had something to do with the mediocre results.
I have dreams of a fancy solar oven hooked up to solar panels and a heat storage center, with little pipes that run hot water from the super-thermos to the yogurt, like a little solar powered yogurt radiator.