Homemade Miso Making Chronicle – 6 Month Fermentation Update


homemade miso making chronicle 6 month fermentation update
I made my very own homemade miso for the first time in November of last year. It ended up being quite a labor intensive process since I made about 40 pounds worth!! I brought back a giant cedar miso making bucket from Japan for it, and I was determined to fill it up! You can read all about my miso making adventure here. As it sits fermenting, I still have no idea how I am going to eat it all. Especially since I made homemade chic pea miso a couple month later! I’m going to have to go on a miso giveaway frenzy amongst my friends and colleagues, and even then, I will probably have more miso than I can handle. Although, that’s not necessarily too bad of a thing. I can use it in cooking more generously than ever before. Yay!

Now that I jibber jabbered enough about miso making, I wanted to do a 6 month update on the fermentation process. I hadn’t opened the cedar barrel at all since 11/27/2015 so I was quite excited to see what was happening. Why a 6 month update? Well, traditionally miso is opened up after about 6 months to mix it from the bottom up. This process is called “Tenchigaeshi” which literally means flipping upside down. This promotes even fermentation by mixing and aerating the miso. To flip, you would take the miso out of your fermentation container and place it into a separate, sterilized container. Then you would wash and wipe the original container with some vodka to sterilize it again. Next, you would put the miso back and seal it off all with the same method you used when you made it originally. You can view the original thread here.  

homemade miso making chronicle 6 month fermentation update
However, after all that explanation of the “Tenchigaeshi” step, I’m not going to do it. Why? Because according to a Japanese miso maker, for homemade miso, the containers you are using are small enough that it’s not even necessary. The Tenchigaeshi is mainly for miso makers who use enormous barrels. So you can certainly flip it if you’d like, but it’s apparently an unnecessary step and I’m not going to bother. What can I say? I can be lazy sometimes, especially when a pro miso maker tells me I can be.

Don’t worry, I still want to see what is happening under the covers, so I will show you how the miso currently looks. First, I checked the miso that I put in mason jars. They both had crystalized salt and tamari that had ran down the sides. If you remember, these jars were not completely sealed to let them breathe and avoid bursting from the fermentation gas building up. As miso ferments, a dark umber liquid rises up, usually pooling at the top. This is tamari. You can see why tamari is gluten free because it’s just a byproduct of miso which usually doesn’t contain any gluten, except for barley miso that is. My mason jars were so packed to not let any air have contact with the miso, that the tamari had risen up and mixed with the surface salt. Then it ran down the sides and crystallized. I wiped the jars clean with vodka, and decided not to open these, as their surfaces are packed really nicely and I can’t see any mold forming inside. So on to the miso barrel! 

homemade miso making chronicle 6 month fermentation update
The miso barrel was just how I left it last. Clean, with no leakage whatsoever. I took off the paper dust cover and then the cedar wooden lids. The bright white salt bags, which were used as weights greeted me. 

homemade miso making chronicle 6 month fermentation update
If you don’t seal the miso 100% when you make it initially, it contributes to molding on the surface. But molding is quite common with miso making. It happens all the time, so it’s not the end of the world at all. If you see white mold, it is actually yeast so you can just mix it in. But if you see blue or red mold, all you have to do is scoop out the mold and a generous portion of the surrounding area and throw it out. The rest of the miso is totally fine to keep fermenting.

Now even though I know mold in miso is very common and not an issue at all, I still wanted my miso to be perfect and mold free. I was curious if my kelp lid actually worked. I took out the salt bags. No mold spilling out of the edges. You can see the salt on the edges turned brown and hardened from mixing with the tamari. So far so good.

homemade miso making chronicle 6 month fermentation update
The moment of truth. I peeled off the kelp halfway and dug through the salt layer. No mold period! Hurray! The kelp and salt bag sealing technique worked! There was no pool of tamari yet, but I can see where it had absorbed in the salt layer. 

homemade miso making chronicle 6 month fermentation update
You can see that the color has deepened from when it was made. Those little light colored pieces in the miso are the koji. I wanted to know why there are so many pieces left still so I looked it up. Apparently, if you use brown rice koji, which I did, the little koji pieces tend to remain and not dissolve into the miso. So you have to use a small strainer when melting miso into miso soup if you don’t want the bits in there. Maybe I will put it through the food processor or a food mill to see if it breaks down nice and smooth once the miso is ready.

Time for the 6 month taste test!. It’s a beautiful rich full bodied miso flavor. Even though it is only half way through the fermentation stages, it’s already a very good miso. I’m looking down at my barrel thinking “Man, that is a lot of miso!” Since I have so much, I might start using the mason jar miso now. That way I will be able to tell the difference between the 6 month and 1 year old flavor profile later. 

homemade miso making chronicle 6 month fermentation update
Well, I must say, I’m very happy with the progress. No mold made me happy. The kelp lid rocked! I’m going to cover it back up again and open it up in another 6 months. It will be even deeper and richer in color, perfectly auburn and ready! Can’t wait!! 

homemade miso making chronicle 6 month fermentation update


  1. says

    This sounds weird, but I never knew that you could eat miso on a raw vegan lifestyle! I guess I thought there was some type of heated sauce in miso XD but anyhow, I love the flavor miso lends! I love using it for Asian recipes such as curries and soups!

    • admin says

      Hi Cassie,

      Miso is made from cooked soy beans and fermented cooked rice, but once the miso ferments, it contains loads of probiotics so a lot of times it’s considered a living food in raw foods. When you use it in raw foods, you won’t heat up the miso high and kill off the probiotics. But even when cooking miso soup the traditional Japanese way, you are never supposed to boil over the miso. You turn off the heat once everything is cooked in dashi + water, and melt in the miso at the very end. It’s interesting that they figured that out eons ago without any scientific research.


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