Hey, thanks for that. I'm wondering why you've got the inner tray inverted? Just did an experiment with an old heat mat that's been used to ferment heavy mason jars of Kombucha for a couple of years and it got the container up to 36c, so I'm thinking that a newer heat mat would maybe give me a few extra degrees, but I am wondering if I need to be too fundermentalist about hitting exactly 40c, and if a few degrees either way would work fine.
I'm thinking that crisscross stacking of the cobs would fit many more in than a yogurt maker. Great idea.
Anyone using BPA free plastic for cobbing?
I'm actually doing this right now Mick, without the inverted tray. I used an inverted plastic shoe box with wooden clothespins for spacers (to keep the bags off the mat itself), covered with two heavy bath towels, folded in half, and it's been holding at around 104 F, give or take a degree to either side, for 7 hours, with no interference on my part at all. When it gets too hot for my comfort I remove one single layer of towels and it stabilized back to 104.