In this third batch I used the same protocol of cooking and mixing but placed the cultured beans in a bread-pan (about 4 inches deep) and created 'air channels' in the beans with sterile utensils.

It turned out pretty well. Digging into the lower beans revealed a really good cover of bacteria. The top beans dripped off or dried early in the incubation so they did not have any growth on their superior surface.

I dug into the bottom-right corner of the breadpan and found consistent gooey beans.

I googled Bacillus subtilis to learn more about it and came across "MicrobeWiki", a very informative site about the characteristics and capabilities of a host of microbes. Under its B. subtilis entry I learned:

"Bacillus subtilis bacteria use their flagella for a swarming motility. This motility occurs on surfaces, for example on agar plates, rather than in liquids. Bacillus subtilis are arranged in singles or chains. Cells arranged next to each other can only swarm together, not individually. These arrangements of cells are called 'rafts'. In order for Bacillus subtilis bacteria to swarm, they need to secrete a slime layer which includes surfactin, a surface tension-reducing lipopeptide, as one of its components (Schaechter 2006)."

Since it moves so readily on surfaces, that could explain why it is so quick to cover the soybeans, presumably monopolizing the real-estate from other bacteria or fungi. I'll still boil all the utensils, regardless.

 The wiki also says B. subtilis is used as a fungicide!

2nd Batch

I took some pictures in the making of the second batch; I was too excited with the gooeyness of the first batch to think about pictures.

I used the same protocol in soaking, pressure-cooker steaming time in the crockpot as the first batch. I did one small thing different, even though the recipes said not to. I took a cupful of soaked soybeans and chopped them for a second or two in a food-processor: it didn't come out in uniform pieces, but it was only to experiment. I wrapped that cupful into a cheese-cloth sack and put it in the pressure cooker with the other, whole, beans.

The beans as they look after soaking and cooking.

This time I divided the whole beans into three jars instead of the original two, as there wasn't enough aeration to the bottom of the beans in the two jars for uniform growth. I used a sterile spoon handle to create a channel through the center of the jar to allow more surface area to be exposed to air. 

I saved a little of the Bacillus subtilis starter for the chopped soybeans from the cheesecloth sack. I admit, I did not use an aseptic technique getting them out of the sack -cheesecloth is tougher than it looks. I tried to mix it and fluff it up as much as possible, but it resembled clumpy bean paste as I put it in a fourth jar.

The beans are covered in a white of Bacillus subtilis after 20 hours in 108ºF water.

After about 18 hours with loosely topped lids, the whole beans turned out as good as could be expected, not entirely covered with fuzz, but good enough; there wasn't an ammonia smell this time.

I regret that I didn't take a picture of the mashed soybeans, as they turned out quite differently. It appeared spotted with dark centered growths, much like one finds on old cheese or in a petri dish. I discarded it, though it smelled the same and had the same stringiness.

Total fermented batch.

I'm doing a third batch and will likely try more using black soybeans, purported to have greater health benefits than classic soybeans.

Bread pan, with one separation started, to be covered with tinfoil with holes

In this third batch, I used a bread pan, separating the beans with a sterile spatula and meat thermometer. I doubt it will allow much deeper growth, but I figure I'll leave the remaining beans to germinate after I skim the top ones.

Success?

Natto goo looks like a cross between 'Aliens' and 'Spiderman' goo.

8 AM, 13 FEB 14: I looked in the jars this morning and saw the requisite "white fuzz" on the beans near the lid; the one's near the bottom had no growth on them at all. I scooped out the ones that looked ready and gave them a stir and they quickly became an uncontrollable web of slime. Lifting the scoopful too high lent to wisp of string floating out across the room on a current of air from the space-heater. The mess was stuck to my fingers, to the fork, bowl and nearly the furniture.

Mushing the beans was a little more difficult than I expected: they could have used another half-hour in the pressure cooker. They smelled very much like ammonia; they smelled like a particularly skunky homebrewed beer. 

The taste was similar to that same homebrew, it seemed like there was the tiniest effervescence on my tongue among the viscous slime. Any hint of original soybean flavor is lost to the slime. I ate the bowl and felt mildly queasy as the new flora introduced themselves to the regulars like a contingent of Yakuza walking into "Eructor's" truck-stop.

Its fairly filling, but definitely could offend many nearby. Another website claims the ammonia smell means it is over-fermented.

I fed the bottom half of the jars to my dog, who can't seem to get enough; we'll see how he feels about it in a half-hour. I'm sure I'll regret this as new aromas arrive from him this afternoon.

For the next batch I think I'll try to separate the beans into halves, or chop them a bit in a food processor to make more surface area. I'll use an air spacer in the center of the beans so they can all ferment properly.