OK. So I thought I had become an expert at making natto but apparently it was beginners luck. Even the oriental grocery store knows little about natto. When I bought it for the 2nd time the same boxes were sitting in the refrigerator. The expiration date was several months from now. The problem was the date was for keeping the natto frozen and it was being sold as refrigerated. By the time I got my 2nd batch home it was already too spoiled for making natto but I've learned a few tips since then:
One thing I learned (I will post links at the end) is that the spores I ordered can tolerate very high temperatures and can even survive being boiled for up to an hour. Though to be safe you should not exceed 175 degrees F. when inoculating.
I reasoned that the opposite was true and that the naked spores could be killed instantly as opposed to being protected by being in the beans. Nothing could be further from the truth and one website went so far as to say the spores should be shocked by inoculating while the natto is steaming hot, much like the way some seeds proliferate after a forest fire. No wonder my natto from spores failed!
I was also worried that maybe my natto had failed because of the honey. Honey is sterile and I thought maybe the honey had steralized them. Though neither of the links I am about to post recommend using honey they do recommend using salt for minerals and sugar or molasses to help give the spores a head start in addition to the heat shock treatment.
I also read that Bacillus subtilis, the strain of bacteria that produces natto is somewhat essential to the human gut and that it is very rare, only found in a few cheeses and very few other foods. Though most bacteria are killed by stomach acid, Bacillus subtilis spores survive the journey surprisingly well and once introduced proliferate in the small intestine.
Also natto is one of the few fermented foods that is alkaline, a PH of 9.0 and virtually every other fermented food is acid. For more information kindly read the links below:
https://www.seriouseats.com/2017/07/obsessed-ann-yonetani-natto-nyrture.htmlhttp://www.tahoescience.org/wp-content/uploads/2011/10/LTFedEvent-2008-natto-making.pdfThanks for putting up with my natto obsession.
surfsteve.