Ok, here we go:

The 10 scientifically researched benefits of eating miso 1. Contains all essential amino acids, making it a complete protein. 2. Stimulates the secretion of digestive fluids in the stomach. 3. Restores beneficial probiotics to the intestines. 4. Aids in the digestion and assimilation of other foods in the intestines. 5. Is a good vegetable-quality source of B vitamins (especially B12). 6. Strengthens the quality of blood and lymph fluid. 7. Reduces risk for breast, prostate, lung and colon cancers. 8. Protects against radiation due to dipilocolonic acid, an alkaloid that chelates heavy metals and discharges them from the body. 9. Strengthens the immune system and helps to lower LDL cholesterol. 10. High in antioxidants that protects against free radicals. So.....Today, 6th October 2015, I made Japanese Miso, using Soya beans, Koji rice and coarse salt....

Soak the dried soya beans overnight. I used 400 grammes.


I then cooked the beans (in batches) in a pressure cooker for 20 minutes each batch. Otherwise, without a pressure cooker, it takes around 4 hours simmering....


While the beans were cooking, I mixed 400g of Koji Rice with 165g of coarse, natural salt.


This is a close-up of the Koji rice (Rice inoculated with the spores of Aspergillus oryzae, a fermentation culture. It's available online). I have mixed it well, with the salt...


Reserve some of the cooking liquor. You will need this to make a mix of an ideal consistency....


Once all the beans are cooked, mash them well with a potato masher, until smooth and creamy, but don't worry if you miss a few bits, and it's a little lumpy....


...The beans should be cooked enough to be able to crush them easily between your fingers....


The soya bean paste should be no hotter than 40 degrees... any hotter, and the culture won't ferment, you'll kill it off. Just over hand-hot is ideal.


Mix in the rice and salt. Add enough liquor to make the mix malleable. It shouldn't be so dry that it crumbles, nor too wet that it's overly 'gloopy'... Form into nectarine-sized balls.


Hurl the balls one at a time, with vigour into a crock-pot. This could be pottery or glass, but not plastic. Clean out the inside with boiling salted water, prior to use... dry with kitchen tissue...
Hurling the Miso paste balls hard, eliminates air pockets.


When you have treated all the miso to a pounding (!) flatten the surface well, and tamp down with a well-cleaned, flat-bottomed object. This could be a meat tenderiser, base of a bottle or just the back of your hand. Cover the surface (in particular, the edge where the miso meets the crock-pot) with a good sprinkling of salt. This prevents microbes getting in and 'fouling' the fermenting miso.


Cover well, right to the edge, with a double layer of clingfilm. Place a flat plate on top, and weigh it down with some substantially heavy material. A half-brick, or several good, smooth, scrubbed stones. Wash the weight(s) well, wrap in kitchen tissue, and enclose in a clean, plastic food bag. Rest on top of the plate. Cover the crock-pot with a thick sheet or two of folded newspaper, then fasten on the lid. label the crock-pot carefully. I put the ingredients, quantities, date of preparation,and what it is. Because now, you have to leave it in a medium to cool dark place (15 - 22 degrees C) FOR A WHOLE YEAR.

It's not so much the time fermenting, although that IS a factor but it's also the ratio of ingredients that determines the type of Miso you eventually get.

I found this article, which is quite interesting...

ETA: This article, however, is a total gem!