So, as I started proofing today's batch of 50% whole wheat sourdough, the wife asked whether I was going to bake in the solar cooker that the boys and I made up a couple weeks ago. Hmmm... So, had to go with it. Maximum temperatures I have seen with it so far are 150C, and as it starts out at ambient temperature and takes about 1/2 hour or so to get up to cooking temperature, did some quite guesstimating as to how long I should allow the dough to proof. Decided that about 1/2 hour was probably plenty, as my primary ferment was a few hours longer than initially planned, and taking into account the increased final rates of fermentation before the dough temperature was high enough to kill the yeast. Dough was my 'standard' ~70% or so hydration, flour, ~2% salt and ~25% starter, all approximate.
This is the setup I used. About 44% more surface area than that described at: http://images2.wikia.nocookie.net/__cb20080804044346/solarcooking/images/9/9c/Fun-Panel2_Instructions.pdf I used two pyrex bowls with a seal for my greenhouse, and a simple enameled black pot as my heater.
Today's max cooking temperature. I had temperatures ranging between 120C and 150C, and baked for almost 3 hours, with final bread internal temperature of about 85C.
I was initially going to make 2 loaves, and ended up putting them together to fit into my solar cooker pot. Forgot to slash them before baking.
And my crumb shot. This loaf has been my sourest yet, since moving to Taiwan, probably due to the longer primary ferment, as well as not needing to keep the dough in the fridge during said ferment, seeing as it finally has cooled down a bit for the 'winter'. The long, slow bake has made quite a soft loaf, which my kids like, though my younger son has complained that it is still not sour enough for his tastes. Oh well, at least the intra-family variation in preferred bread flavours ensures that someone will like the bread no matter how it turns out! The flavour is quite unique, but my vocabulary is limited enough in this regards that I am not sure how to describe it. Am also trying out some new organic whole wheat flour which works differently from anything I've tried before, so too many variables have changed with this for me to know what is causing what effects in the flavour. Definitely will try this again, though probably a batch of buns that will cook faster!
If anyone out there has experimented with slower, cooler bakes such as this, please let me know!