sweet miso troubleshooting

[WWFSM]

Hi guys, I need a bit of help with my sweet miso. It's my first time making miso, so of course I'm nervous.

I followed the recipe for sweet miso in Art of Fermentation, using a mixture of beans (no soy), and commercially prepared koji rice (which I know is viable because I make other things with it), and salt.

I left it at room temp for 6 weeks, occasionally scraping the mould off the surface. I dugg some out today and I'm not happy with it. It smells and tastes like sour beans, koji mould, and a hint of miso. Not very salty (but I did measure the salt as per directed).

There is nothing repulsive about it, so I ate some. It tastes like it smells, only very mild.

It definitely had some fermentation, as the bean mash changed texture and smell. But is this the right fermentation?

What do you think? Put it all back in the vat, press out the air, cover the top with salt, replace the tamari, and leave it for another month? Or is it better served to the chickens (who think it's the yummiest thing since lizards)?

Please help.

[WWFSM]

I should mention I went through my regular ferment-went-wrong checklist:

Water: well, very deep well, like a ridiculously deep well, think deep well and times that by three. The water is filtered, and uv filtered. There were no contaminants that affected other fermentations started at the same time, and for the miso, I only used the boiled water from cooking the beans.

Salt: Fine sea salt, no iodine, measured by weight. It's a brand that works well for other ferments.

Temperature: The beans were cooled before mashing and were below body temperature when the koji rice was added.

The fermentation temperature is between 67F and 71F, with a few days dipping below 65F. That's why I left it longer than the minimum 4 weeks before digging some out.

Ingredients: The beans were about 2 years old, still good, and viable (they grow if planted in the ground). This koji rice has worked in the past for fermenting other things like shio koji.

Method: The beans were only soaked about 6 hours before cooking, but I did cook them longer, until they were mushy. Because the beans were different kinds, I soaked and cooked each kind separately so that the finished texture would be the same. I coarsely ground the cooked beans, mashing about 20% and leaving about 10% whole.

The beans were washed several times (about 8) before soaking and again after soaking.

They were boiled, not pressure cooked.

Very careful to blend everything well, and to keep the air out when packing the vat.

Cleaning: The crock, and lid were new and cleaned with eco-friendly dish soap, then rinsed several times and then rinsed with boiling water. The rock for weight was used for other ferments, but has been bleached with H2O2 since then. I scrubbed it with salt and then rinsed it with boiling water.

No antibacterial soaps were used except for the H2O2 cleaning on the rock.

Contaminants: Other than the surface mould, nothing could have got in... the lids include the inner lid, the rock, the layer of tamari liquid, a layer of cling film, a towel, and the top lid to the crock... There was a lot of mould growth and I scraped it off two or three times during the fermentation.

Air: There was a layer of tamari from fairly early on, it wasn't much, but I don't see how air could have been the factor here... but I could be wrong, this is my first time with miso.

So there you have it. Air or temperature are the only things I'm thinking could be an issue... unless I'm missing something.

Anyway, I put it back in the crock. Pressed it down, and put a rather large handful of salt on top. strained the mould off the tamari and replaced it. I scrubbed the inner lids and rock again, salted them before adding to the vat. I'll give it a few more weeks... but I would really like to know what's wrong with it.

[WWFSM]

Update on the miso. Tried it again today and it actually tastes like miso. I even dragged my Japanese friend over to my house to make certain my taste buds weren't playing tricks on me. She couldn't stop eating it and took a bunch home.

I'm so glad I repacked it and let it sit longer. Still a slight sour bean taste to it, but no longer overpowering. Quite pleasant actually.