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incubation experiments.4

1 Aug

Corrigan cleaned behind the counter at the bike shop the other day, and I snagged a big old thermos he was going to throw out. Instead of going through the whole yogurt making process, I filled it with hot water from the faucet, closed it up, and wrapped the whole thing in an insulation blanket I got from American Science & Surplus.

The temperature at 8:45, when I left for work, was 110°F, and when I returned home 11 hours later, at 7:45, it was at 95°F – a loss of only 15°F! I’m hopeful – today I’m going to heat some water on the stove to about 125°F and try a yogurt incubation experiment for the rest of the day. (Remember – the ideal yogurt-making temperature is 110°F.)

incubation experiments.2 & 3

30 Jul

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.

incubation experiments.1

10 Jul

When I make yogurt at home, I wrap it in a couple of dish towels and set it right above the pilot light overnight. This keeps it at about 115 degrees, which is a little cool but close to perfect for yogurt incubation.

When I’m on my bike, it won’t be so simple. So, I’m in an experimental stage of yogurt incubation tests. My uncle is being a big help, encouraging all sorts of set-ups with black plastic bags and using water heated by the sun, and I’m excited by one of the ideas he just recently came up with.

This weekend’s experiment was incredibly simple, and surprisingly successful, although I had to modify it a big when the cloud cover started rolling in later in the afternoon…a natural shift in the weather that I’m going to have to be able to adapt to on the road, too.

I was housesitting in Oak Park, in a house with a backyard that got full sun all afternoon, so I took advantage of the nasty summer heat (sympathies to the East coast, where it was worse) and just set my jar on the rocks.

I think it would have been better to wrap it in a black plastic bag. The jar wasn’t actually that hot to the touch (I left my thermometer in Hyde Park), so I think the glass and white yogurt actually reflected the heat I wanted insulated. I had to leave once the clouds came, so I heated up a big pot of water, started preheating the oven, turned off all of the burners, and shut the yogurt in the oven in hot water, hoping their new oven kept its heat better than mine.

It did! The yogurt came out runnier and grainer than usual (the latter I am pretty sure is because of this kind of milk, I’m not a big fan, even though it is raw), but it did sour into yogurt, so I’m encouraged by future plans of solar ovens in various forms. Stay tuned!