Miso - white something part 2

[terji]

Hi,

trying some sweet miso to get a taste before my long term ones are ready.

This is [soy koji]:[soy beans]:[salt] 10:10:2 and I am keeping it in around 27C (80F) in closed jars I am burping once a day.

This appeared on the top I scraped it then it came back I scraped it again and now it is probably gone.

Just want to know if anybody knows what it is

Thanks

pic is too big you can scroll down to see more of the white stuff

[Christopher Weeks]

Looks like kahm yeast to me.

[bjdmytro]

It might be kahm yeast, as Christopher says, but that would be unusual for miso, since miso shouldn't be acidic enough to support the the growth of kahm yeast. That might mean you have some laco-fermentation going on in the miso and it could end up with a sour flavor. Ideally, a white miso should have a sweet, nutty, and aromatic flavor.

It might also be aspergillus oryzae (koji mold), especially if it gets white and fuzzy. Did you use fresh koji. I grow my own koji and use it fresh. So, I often have aspergillus oryzae grow on the top of my miso, and it will even produce spores. Aspergillus oryzae is white when it is growing and turns olive green when producing spores. I simply scape this off and discard, with great quality miso underneath it.

[terji]

Hi,

yep, I used fresh homemade koji, miso looks/smells/taste ok but my oldest is 3 months old so I do not really know that much...

scraped it twice and did not came back.

Thanks!

[terji]

Hi,

so the problem above I am pretty sure is just a kahm yeast but I have another specimen to identify -

I was mashing, tasting, reusing the same spoon and generally doing stuff I probably should not with the misos.

Appeared on the sides of the container as far as I was pushing with the spoon... smells nice, tastes nice so far...

Looks like this does not really progress much and does not appear on the top...

[RobertN]

Hi terji,
I observe the same phenomenon in my kome miso, now 6 Month old. Mine also smells good. I wonder what it is....
Did your miso lost water during fermentation? Mine did, that’s why I thought it could be locally concentrated salt.
Or it might be koji (Aspergillus oryzae)?

Does anybody have an idea?

Merry Christmas!

Robert

[cerbu]

tyrosine crystals, not something bad

[RobertN]

Thanks cerbu,
Interesting thing these tyrosine crystals! Didn’t know that it’s the same in aged cheese and aged bacon!
Best wishes
Robert

[terji]

Thanks! Looks like a good stuff too; from wiki:

A number of studies have found tyrosine to be useful during conditions of stress, cold, fatigue,[19] prolonged work and sleep deprivation,[20][21] with reductions in stress hormone levels,[22] reductions in stress-induced weight loss seen in animal trials,[19] and improvements in cognitive and physical performance[17][23][24] seen in human trials.

Tyrosine does not seem to have any significant effect on cognitive or physical performance in normal circumstances,[25][26] but does help sustain working memory better during multitasking.[27]