I have tried making natto at home. It has not obviously gone wrong, but it tastes nothing like the bought stuff. Is there an objective way to tell if it has fermented properly, rather than having gone off?
I use the following procedure:
- Soak beans overnight
- Boil beans for ~3 hours
- Leave to cool in saucepan (do not open lid)
- Add shop bought natto as a culture, being careful to add nothing else to maintain sterility
- Leave in a warm place for 24 hours
After this time I taste it, it is not obviously rotten but it does not taste like any shop bought natto I have tried. It is quite possible that I have just made not very good natto, as is to be expected the first time it is tried. However I cannot rule out that I have done something wrong, and it is contaminated. I have done a certain amount of brewing and yogurt making, and with those I am familiar enough with the product to tell if it has worked. Is there any objective way to see if it worked, or anything to look out for in the product to determine if the correct fermentation has occurred?