Which koji should I buy?

I’ve been asked, understandably, which koji to buy. A choice of 9 different strains may be a bit overwhelming when one is just starting out.

The most important thing to know is what you are most likely to make with the koji. Do you want to make barley miso, rice miso, soy sauce, amazake, etc.?

Generally speaking, rice koji will grow on soy beans too. It is a bit like buying vegetable seeds in southern Spain. They are meant to be grown there, but they will also grow in Austria – albeit just not as well.

In Japan koji has been bred to fit different applications, i.e. for soy sauce, for different misos, sake etc. So some strains have been bred to produce a lot of amylases, some to produce a lot of proteases, others to grow fast and on “difficult” substrates.

If you are planning to make sake (needs strong amylatic power) and soy sauce (needs lots of proteases), you are best off buying two strains. If you want to make rice miso and amazake, you are served well by just buying one strain.

I am sure can grow barley koji on rice too – might be worth an experiment!

The 9 strains explained

Which of the 9 kojis you should choose really depends on what you are planning to make.

Strains for miso:

Light Rice Koji

This is the strain to get if you plan to make short term sweet misos, amazake and/or sake. Sweet misos are misos which don’t ferment for very long (from 2 weeks to two months) with a relatively low percentage of salt.

This strain has strong amylatic power.

Red Rice Koji

This strain has been bred to best suit long term rice misos, also called red rice misos. These misos ferment from 6 to 12 months and contain more salt.

Compared to the light rice koji, this one has stronger proteatic power but less amylatic power. The strong proteatic power helps to make the miso as delicious as possible.

Barley Koji

This strain is probably my favourite to make. It just smells so good! Incidentally barley miso (also called mugi miso) is my favourite miso, too. It ferments from 4-12 months.

As the name says it is best suited for barley, which is a more “difficult” (for the fungus) substrate than rice. So this strain has been bred to grow easily on pearled barley.

Amylatic and proteatic power are both at a similar level.

If you’d ask me which strain you should buy if you just want to buy one – I’d say either this one or red rice koji, depending on which miso you like better.

Soy Koji

Some misos are made exclusively with soy beans – a difficult substrate for the fungus. These misos also take the longest to ferment, from 12 to 24 months. This strain has been bred to fulfill the needs of this application, it grows best on soy beans and has strong proteatic and medium amylatic power.

Strains for soy sauce:

Soy sauce Koji

If you are planning to make soy sauce, I really recommend getting this strain.

Soy sauce is made by toasting wheat, breaking it up, mixing it with steamed soy beans and then growing koji on it. Needless to say that is not an easy substrate for the fungus, but this strain has been bred to grow best on a substrate like that within a considerable time.

My supplier has this strain running under the name “three-dia”, because it takes only three days to grow, other than the usual four days for such an application.

With soy sauce there are more factors in what is needed from a strain. Low sugar consumption is wanted – to leave more in the final sauce/for yeasts. Also high proteatic power is needed, so suppliers breed specifically for these needs.

Mild Soy Sauce Koji

The normal soy sauce strain can be really vigorous, and for that reason it is prone to overheating. This strain grows more slowly, which is why beginners might find it easier to use. This is the reason it is called “mild”. The soy sauces you make with this strain will be no less strong than the ones you make with the normal strain.

A. Sojae

This is actually a different species, called Aspergillus Sojae. I provide this strain for people who want to change it up a bit. It is traditionally used for pale soy sauces and is said to have a different characteristic smell and taste.

If you are making soy sauces – try it! If you are starting out and want to make miso it may be better to stick to other strains. However it might be an interesting experiment to make miso with this one.

Other strains:

White Koji

This is a strain that is primarily meant for Amazake. I think of all the Koji strains I offer, this one smells best: flowery and mushroomy. While this strain is primarily for Amazake, I have made miso with it as well and it was good, too!

Black Koji

This is not A. Oryzae, but A. awamori. Traditionally this fungus is used for making shochu, a distilled drink either made from rice, barley or sweet potato. Unlike regular Koji, it produces citric acid. The acid helps to lower pH to make the amylases more effictive (their optimum is between 4.2 – 4.8 or so).

So this strain is for you if you want to make shochu, or if you want to experiment with a strain that has a black color and produces citric acid.

I hope this article helped to make your choice! If you have any questions, ask away :)

This Post Has 103 Comments

  1. Hi :⁠-⁠)
    I read the answers above.
    After some years of tests and experimentations, do you still recommand only spores of light rice koji, or the sojae for dry aging beef raw meat ?
    Thank you

    1. Hi Ronny, not only, but I think they are best suited for the purpose.

  2. Hello, I am planning to make miso paste on my own however, koji rice (with fungus aspergillus oryzae) is really hard to find and some are from overseas which makes it so expensive. I can only find the red koji rice or red rice yeast as what they called (with fungus Monascus purpureus), my question is if it’s ok to use for making miso instead the white koji rice? I know you recommend it but I’m just uncertain if you are talking about the same red koji rice cause they seem have different type of fungus?

    1. Hi Peejay,

      sorry to say that I have no experience or knowledge about making miso with monascus purpureus rice. Our red rice koji is something different, it is A. Oryazae which is meant for red miso (= long aged rice miso). But do let us know how it went!

  3. Hi Viktor,
    I would like to make sweet miso, but not out of rice. Shell I take better the white koji or the light rice koji spores? Besides this I also wanna make soy sauce and savory miso (out of barley and different other grains) – can you recommend one strain for both or is it better to buy two different strains (all in all three of the same species)?
    Thanks so much for helping and this super website!

    1. Hi Lena,

      generally you can use the strains for miso interchangeably (so you can buy the white koji for the light and the savory miso), but for soy sauce I’d strongly suggest to get a soy sauce strain. After all, you are going to put in so much work for the shoyu, better to use a fitting strain to make sure it works out well :)

  4. and which has the strongest amylatic power ? Light rice or white koji ?

    1. The light rice is generally more enzymatically active.

  5. Hi Viktor,
    when you say that ” you are best off buying two strains” for sake, how so ? Do you grow the spores on 2 separate substrates, then mix them, or do you grow the spores on the same substrate ?

    1. Hi Luka,

      what is meant by that is, if you want to make Soy Sauce and Sake, you should buy a strain for Soy Sauce, and one for Sake.

  6. Hello Viktor,
    Thanks for such an incredible website, first of all.
    I am planning to try my hand at growing koji for the first time and getting some ferments out of it. I want to make sweet miso, amazake and shio koji.
    From reading your explanation, it seems that the light rice koji spores will be sufficient for the miso and amazake. My question is, do you think they will also work for the shio koji? Or should I get a different strain for that purpose?
    Thanks and best,

    1. Hi Alex,

      thanks for the compliments :)
      The light rice koji is very suitable for shio koji, no need to get a different strain.


  7. Hi Viktor, amazing information. For A. Sojae, I have trouble keeping temps down. Even when putting koji outside in winter (California winter though). Any tips?

    It quickly spikes to 40C about 30 hours after inoculation no matter how many times I mix it or put it outside with a damp towel over the kojibuta in 13C ambient air temp. Seems like it needs its own air conditioning…

    1. Hi Evan,

      That problem should be easily solved by making thinner mats. It sounds to me that you are making rather thick ones.
      I used to have this problem when I started out as well, but thinner mats solved it. It’s a bit of a shame, because it means you can’t make as much at once, but so it goes.

  8. Can you give some miso recipes? Or even a how to guide like the soy sauce one?

    1. Hi Ion,

      I started working on an article on this topic, but I hardly find time to continue with it. Until I finally get this done, I recommend to get one of the many brilliant books on this topic. Kirsten Shockey has written a good one; there’s the classic “The book of miso” by Shurtleff and Aoyagi; and the Noma Guide is good also.

  9. Hi Viktor,
    Thank you very much for your great homepage and the awesome spores. I have already experimented with different strains of you and right now I’m making a batch of amazake with the white koji spores. The smell during the grows of this fungus is just amazing.

    Above you write about the black Koji (A. awamori). Do you also sell this strain? I would be very interested to experiment with it :-).

    Also, I’m wondering if you could recommend a specific strain to ferment meat (f.e. beef). Would the strain used be different when fermenting raw compared to cooked meat?

    Kind regards,

    1. Hi Livia,

      unfortunately we don’t/can’t offer the black strain, as our supplier is protective about selling it publicly.

      For meat garums I recommend A.Sojae. You’d grow it on barley or bulgur, and then mix it with the meat, some water and salt of course. The usage of the strain is not dependent on whether the meat is raw or cooked.

      Kind regards,

  10. Thank you Viktor.
    I tried already, but the quality taste is very far from the Shochu which bought from the shop. Hi hi
    Any way, I bought the Tane Koji and make Koji rice to brew the Sake. It works.
    But I got question that, The Koji rice to make Sake is done, but can I use Koji Tane to make Koji Tane and use that Koji Tane to make Sake?
    Thanks Mate.

  11. Hi Mate,
    Its amazing web site I ever seen, Thank you very much for your effort, I read all and see how patient you are.
    Please do me a favor.
    I’m now very interested to make Sweet Potatoes Shochu. But I got almost nothing on internet. Concerning to this project.

    I checked all Japanese Sochu subject, but there is now one talk about it in detail recipes. They just talk simple like to use Black Koji to make Awamori then distill it…
    Can you help me to run my project by showing me how much Black koji need, how many day need, and how much Sweet potatoes and when to put in…

    I’m looking to hearing from you soon.

    Best regard

    1. Hi Lee,

      unfortunately I can’t provide you with a recipe, and I don’t know where to get one. It looks like you’ll have to do a lot of experiments by yourself. But I think that’s OK, because this way you will develop your own style of shochu :)
      If you are totally new to making Koji, I recommend to learn the craft with white rice and then start doing experiments with sweet potatos.

  12. Can you inculate rice with Soy Koji to make make a super proteatic Koji and then go the “normal way” of making Miso or should you stick to the red rice/barley koji?

    1. Hi Nikolaus,
      it’s better to stick with strains that are meant for rice if you have the choice. The breeding effort behind Soy Koji is that it grows well on beans.

  13. If I use soy sauce koji to make soya sauce, then which color should my beans get when the inoculation process is done?

    1. Hi Isabella,

      either yellow/green or white. The mycelium is white, and the spores are either yellow or green. In Soy Sauce making it doesn’t matter so much if the koji sporulates or not.

  14. Hi Victor,

    I’m making Acorn Miso. (no soybeans), What koji would be best for that? Currently I’m trying long term red barley koji. And where can I buy the Koji you recommend? I live in Vermont. thanks!

    1. Hi Mark,

      you can buy it here!
      I would try the soy koji first. If that doesn’t work well, the white koji has proved to be a good allrounder for any miso.

    2. Hey Mark, how did that go? :-)

  15. Hi ,
    I would like to know which koji would you use for making chickpea miso and what would be the ratio and time of fermentation?
    thank you

    1. Hi Luz,

      it depends. Are you making it with rice koji, barley koji, or just straight chickpeas?

      For Rice: either light or red rice koji, depending on whether you want to make a light or a red miso.
      With barley: barley koji.
      Straight chickpeas: soy koji.

  16. hi!

    I’m trying to get some fava beens going to make my own douban, which strain of koji which be the most appropriate? I was thinking barley, right? I remember the mould on the beans being yellowish.

    Thank you!

    1. Hi,

      I recommend to use the soy koji for that! it is bred to work well on beans.

  17. Thanks Viktor!

  18. Hi Viktor,

    I would like to try curing meat with koji. I have tried it with a shio koji wet marinade, but im not happy with the results. I have seen that some people grow the koji, mixed with rice flour, on the surface of the meat (keeping it at high humidity and suitable temperature). Which koji strain do you think would work best for this? Thank you!

    1. Hi Talia,

      I would either use the light rice koji, or the sojae for that.

  19. Hello,

    I made my first batch of koji with your red rice koji on rice. The smell is a bit like cat urine. Other than that it looks fine. Is that ok?

    – Tony

    1. Hi Tony,

      what you are smelling is Ammonia. It’s a sign that your rice was too wet, which made it possible for bacteria to grow. Often it is bacteria from the genus Bacillus, because they survive steaming. Unfortunately, there are safe species from Bacillus, but also toxin-producing ones. It’s not possible to say which you got.

      In your next batch, make sure that no water is pooling in your tray. Either use 2-3 layers of kitchen towel, or maybe a wooden box.


  20. Dear Viktor,
    Japanese ladies have such beautiful and flawless skin. I believe that adding koji to a daily routine helps a lot, I would like to buy some to add to my skincare, but am very unsure what to buy, I wonder if your knowledge and expertise in this area would run to skincare?
    Saiko no negal o komete,

    1. Dear Rachel,

      I am sorry to say I don’t know anything about skincare.


  21. Thank you very much, Viktor!
    I’ll be your costumer :)


  22. Hi,

    which koji is gluen-free / suitable for gluen free preparation like miso, soy suace , ect?….
    as I can see from the ‘ingredients’ section on the image, are all grown from potato starch,
    and so are suppose to be gluten-free, but I’d like to be sure.

    1. Hi Paolo!

      Our supplier grows their spores on both rice and barley.
      Light Rice, Red Rice and White Koji is grown on rice, the rest is grown on barley. If you buy any of these three, you are safe. The others probably contain trace amounts of barley.


  23. Thank you so So much Viktor that’s so helpful! Maddie x

  24. HI Viktor
    I’m so sorry if this question has already been answered but I’m looking to make breadso? The recipe calls for Aspergillus oryzae Koji Tane but I’ve read through all the ingredients of all of your types of Koji and description and can’t find one referring to itself as Koji Tane or Koji Tin/ Kin as it is often translated apparently. I might be being very stupid as it just means any A. Oryzae is fine but thought I should check before I botchelize myself for the umpteenth time :)
    Thanks, Maddie

    1. Hi Maddie,

      as you suspect, “Koji Tane” or “Koji Kin” means just Koji (i.e. A. Oryzae) Starter.
      So, to start out, I recommend the white koji, since it’s quite beginner friendly.


  25. Hi Viktor,

    You’re an amazing source of information on all things koji! Thanks for taking the time to create such an informative website, and sourcing excellent spores.

    I’ve got a simple question which I can’t see has been answered elsewhere: If I buy your ‘Organic Dried Koji Rice’ can I use that to inoculate a new batch of steamed rice? Or do I need to start with Koji spores if I want to inoculate rice? I am thinking that if I buy the ‘Organic Dried Koji Rice’ then I can start experimenting with misos, ‘dry ageing’ meat and some of the other ideas from Noma whilst I grow some more koji rice.



    1. Hi Nic! Thanks a lot =) (also, sorry for not replying earlier!)

      Dried koji rice can not be used to make more Koji. We dried (and therefore killed) it before it could produce its “seeds”. If you want to grow your own koji, you have to use the spores.

  26. Hi,
    i am trying to make soybean koji. It starts very good in the beginning, the mold grows very fast and fluffy. But at ~36h it always starts to smell amonia. I also improved my temperature setup so i can guarantee 29-30°C. I dont use any towel or sth like this since i already have 94% RH in my chamber. The beans are in a wooden tray. What else can I do? Maybe try to cook the soybeans a shorter time? How important is airflow in the process? (I use a plastic box, may it be possible that thats the problem and i should just open it a bit?)

    And a final question^^:
    In this video the koji is ready when it has a green colour
    Is this what i am looking for?

    P.S.: I am using the soy Koji spores https://www.fermentationculture.eu/shop/soy-koji/

    1. Hi Lion,

      many people are struggling with their soybeans smelling of ammonia.
      Your humidity sounds very high, and I am guessing that condensation water is dripping onto your beans, which makes it easy for Bacillus subtilis (the culprit for the smell) to grow. You could either try to reduce the humidity a bit, or build your koji a roof :) Maybe just putting a few layers of dry cloth on top of your koji will solve the problem.

      Koji needs air to grow, so you’ll need to make sure it doesn’t suffocate. Since you are making the koji in a wooden tray in a plastic box, it sounds like there is enough air in there anyway. You can try to smell immediately after opening the box. If you can detect anything resembling carbonated drinks (like opening a bottle of carbonated water and smelling immediately), then you’ll need to make sure that more air gets in.

  27. any leads on purchasing black koji spores? super interested in trying it out but I cant find much in the way of purchasing it….

    1. Hi Steve,

      we used to have it, but our supplier does not want it to be sold openly, so we stopped. In my opinion, Luchuensis is superior in taste and very similar.

      1. I used the luchuensis recently and was very happy with it! just always curious to try out new things, and was curious about inoculating some duck breasts with it. I suppose ill have to file that away for a later time. thanks for getting back to me.

  28. Hello Viktor,

    I am planning on experimenting with some ferments, specifically fermented sweet rice. Now, from my research it seems that fermented rice uses a mixes of yeasts as well as molds like the Aspergillus Oryzae (a.k.a Koji) and Rhizopus Oryzae. It seems like the latter is used for making Tempeh as well. So my question to you is, if I wanted to try and make this rice, do you think you could recommend which one would be best, in your experience?
    So far I am leaning towards the Tempeh one and a regular A. Oryzae like the barley one. Also, if you have any other tips of experience you want to share I’d be happy to hear from you.

    1. Hi Sandro,

      if you want to make sweet rice, I recommend the white koji or the light rice koji strain. They are best suited for making Amazake. I am doubtful if it’d work well with Rhizopus.
      Once you made the koji, just mix it with 1-2 parts water and keep it at about 55-60°C for 2-3 hours at least. Some grated ginger is great in it.

      1. Thank you Viktor, I’ll try that :)

        1. Hey Viktor and Sandro,

          I bought the white koji spores here and would like to make a batch for amazake.. should I innoculate sweet rice from the start, or use regular white or brown rice for koji and then make the amazake by mixing that in with sweet rice? Or try both? I think I’ll do that anyway. But still interested to hear your opinion! Thanks ahead and thanks Viktor for this great source of information and excitement!

          1. Hi Kristien,

            Thanks for the kind words.
            If by sweet rice you mean glutinous rice, you can absolutely use it for making koji and then amazake, I would recommend it in fact.

  29. If I wanted to inoculate Korean meju blocks with Aspergillus sojae, how would I go about that? Since there probably isn’t much aeration in the interior of the block, would I just dust the surface or mix the spores with the soybean mash before forming the blocks?

    1. Hi Alex,
      I have no experience whatsoever with Meju blocks, but if I was doing them, I’d dust the surface of the blocks (provided they are cooled down)

      1. Thank you, I’ll try that!

  30. Hi,
    If I would like to use Aspergillus spores to create a nut (almond; brazil) based vegan cheese, and I would only like to let it ripen for a couple of weeks. I am looking for a very complex taste, preferably similar to cow milks cheese. I think the light rice is better if you look at the fermentation time, but the red rice might give a much better flavour due to the high protein content of the nuts.
    What kind of culture should I choose?
    Thanks for your advice!

    1. Hi Dione, sorry for the late reply.
      In this case I’d choose A. Sojae, it produces the highest amount of Protease.

      1. Thanks!

  31. Hi Victor,

    Definitely not ammonia. When drying it had an amazing smell of truffles and fresh yeast which later developed into more salted/cured meat like. I think the smell is absolutely outstanding but maybe not preferable for green coffee. Ill try with luchuensis and white koji. Citric acid is probably something I’m looking for.
    Maybe even will try to send some to Central America and grow it on freshly picked coffee to replace traditional fermentation. I’ll keep you updated :)

    All the best,

  32. Hi Victor,

    Thanks for creating this amazing website and probably the most interesting forum about koji cultivation.
    I bought some koji spores A. Oryzae in UK and experimented growing it to make different types amazake and shio koji with great results.
    I’m working in special coffee industry and I was curious to try growing it on green coffee before roasting. I set up two samples (1.soaked for 12 h in water and steam 20 min 2. Just steamed 20 min)
    Both got pretty decent coverage (no.1 a bit better) after 3 days. I left it in the fridge for 1 day and dried in oven on lowest setting to lower down the moisture level ( necessary for even roasting) and now it smells like cured meat (salami or chorizo) (very umami like) do you think it’s spoiled sometime in the incubator? Should it smells like it ? Do you think there’s other strains more suitable for coffee? It would be the best to produce more floral , higher in sweetness and acidity coffee.

    1. Hi Jakub!

      From what you are describing it sounds OK to me! A meaty smell may be expected, sometimes. Did your beans smell like ammonia at all?
      I think your beans are fine to roast.

      In my experience, the white koji is the most floral strain. I don’t know how the acidity in coffee comes about, so I can’t say if the koji is going to bring more or less of it or if it has any impact on it at all.

      Also, if sometime down the line you are doing bigger batches, please think of me and share a sample, I am also a coffee lover =) I don’t know anything about roasting, which is why I haven’t ventured into the koji / coffee combination yet.

      Kind regards,

  33. Hi Viktor,

    Is barley an OK substrate for A. Sojae? A. Sojae Koji is mentioned in the Noma Guide has an option for making Garum, as it’s high in protease enzymes.


    1. Hi Tony,

      truth to be told, I don’t know. It’d grow for sure, but I can’t really predict how well. You would have to try.

  34. Thank you Victor for your swift answer!
    Reading back through your other answers I think I understand to use pudding rice for the koji rice.
    Do U send instructions with the packets?
    You write cooked chickpeas, is the rice used raw?
    Apologies for asking questions to which you probably have the answers already in thus website, however the internet here is weak and therefore difficult to browse with!!!
    A friend will be ordering for me V. soon :)

    1. Hi again,

      I don’t send instructions with the packets, I post them here in this blog.
      The rice must be kojified first. Once the mold has grown on the rice you can proceed to make miso with it. Do not cook the koji rice!! You will kill all the enzymes that will break down the proteins and starch of the chickpeas.


  35. Hello Victor,
    I am totally new to the idea of making Miso. I only thought of it because where I live in Bulgaria I cannot buy miso in jars only silly soups!
    So I got to thinking maybe I can make it at home.
    Yours was the first and last website I looked at. It is really informative. Thank you.
    So the miso I like most is white miso, however being vegan I already consume enough soya so I would like to make miso with chickpeas instead.
    Please advise which would the best koji for this?
    And are there any tips?

    1. Hi Liska!

      For a white miso I recommend the Light Rice Koji. It has been bred for this very purpose :)
      When you make the miso, use 2 parts Koji rice and 1 part cooked chickpeas. I think it’s a good ratio for this type of miso. Add 6-7% salt and wait for 2-4 weeks :)

      Wish you good success!

  36. If I wanted to make sweet potato vinegar, I should use the black? Where do you get yours? How long would you inoculate the potatoes with it before pressing for booze? You inoculate as,you would any other strain…around 86 at high humidity?

    1. Hi John,

      it doesn’t need to be black koji. We had it in the shop, but we decided to stop selling it for various reasons. One of them is that luchuensis is easier to handle while delivering better results. You can also use White Koji or Red Rice Koji. The important part is the amylases, so you can get fermentable sugars for the yeast. All strains will deliver amylase, some more some less. Luchuensis will also produce citric acid – so it is going to have a special sort of acidity in the end when you make the vinegar.

      And yes, humidity is the same.

      Kind regards,

    1. Hi Jeremy,
      I don’t have experience with that unfortunately. But if I am unsure of which strain to use, I usually opt for the red rice koji, as it’s a great allrounder.

  37. Hi Viktor,

    I never find information about what kind of rice to use, barley and soy beans seems clear as there’s not too many different ones to choose from. But rice.. I mean for mirin they use sweet/glutinous rice but how about the rest, is the koji capable of breaking through the skin of a whole rice grain or not? (could be cooked a bit more in order for it to open more) otherwise what are your suggestions? Just checked in my japanese shop next door: the typical japanese rice (especially organic is quite pricey) so I first wanted to ask for your advice before buying :) thanks already for your feedback/advise! Vanessa

    1. Hi Vanessa!

      I recommend small and round grain rice. I always use the kind that is recommended for rice-pudding (milchreis in german). I never buy Japanese rice, as Italian rice is so near and just as good in my opinion. Originario is a kind of rice that is rather small grained.
      Consensus is that pretty much the only way to make Koji with whole grain rice is to sprout the rice first. I haven’t tried doing that yet to be honest.

    1. Hi Antia!

      I got your comment, but I could not reply right away, sorry for that.
      For your purpose, the red rice or light rice Koji is good. Probably I would first try the light rice.
      And I do ship to Sweden :)

      Kind regards,

  38. Thank you very much for answering my questions. I will optimize to avoid thermogenesis and not worry as much about contamination. I look forward to seeing how it turns out!

    1. I got my spores, and tried out the soy koji, which worked exactly as I hoped on my fava beans. They smell correct and are perfectly fuzzy after just 48 hours, and indeed heat was not a problem once they got started. The next step is a year or so of lacto-fermentation, so it will be some time until I know how the final product turned out, but I feel like starting from spores has been a big improvement to my process, and as you said it has been very easy to get it to grow fast and well.

      Thanks again for the advice, and I look forward to trying some other strains soon.

      1. I am happy to hear that it has worked out :) Thanks for letting me know!

      2. I have started eating the chili bean paste produced in the above comment (using recipe https://www.chinasichuanfood.com/doubanjiang/), and am happy to report that it turned out very well. It needs another year or so of aging to be at its best, but I’m happy with it at 6 months.

        If anyone else wants to try this, I’d recommend the soy koji as Viktor notes above. I also tried barley, red rice koji, and soy sauce koji. None of them were complete failures, but they took longer to grow on the broad beans (especially the soy sauce koji), and I lost some due to bacillus contamination in the meantime. The soy koji grew very quickly. I will try a. sojae as well next time; I did not try it this time.

        One thing I found tricky was getting the moisture right with the beans, typically they were too wet. I found that it helps to soak them NO MORE than 8 hours, and then, immediately after removing them from the steamer, toss them around a bit in a strainer to encourage surface evaporation. This is a similar technique used to the production of grain spawn for mushroom cultivation — fungi are better able to tap into moisture in the substrate than bacteria which rely on the surface.

        Viktor, do you have a preferred recipe for soy sauce? I want to try making that next, with the remainder of the koji I got for this experiment.

        I’m also interested in producing Zhenjiang vinegar, which is a triple fermentation (saccharification with koji -> fermentation with yeast -> acidification with acetobacter). Do you have a suggestion on which strain of koji to try? I was considering the soy sauce koji, but now that I think about it, perhaps one of the strains for making alcohol is a better choice. The end goal is a rich, flavorful vinegar, which makes me think protease, but I need enough amylase to actually produce the alcohol/vinegar.

        1. Hi Alex,
          thanks a lot for the follow up! Interesting stuff. I want to make doubanjiang too this summer :)
          Did you cook the beans or did you steam them? I’m sure steaming would be more forgiving. Ideally in a pressure steamer, to speed up the process.

          I just wrote a new article on how to make soy sauce, but I haven’t released it “officially” since I’ve been wanting to add some photos. You can see it here: https://www.fermentationculture.eu/how-to-make-soy-sauce/
          I’m not sure if I am happy with it yet, the explanation seems a bit convoluted. Please let me know what you think :)

          As for the vinegar, I recommend the Light Rice Koji, it produces both plenty of amylase and protease. Start your Koji at the usual 30°C and once it’s growing, try to keep it at 35°C, this way you will achieve a good balance between amylase and protease (the higher the temp, the more amylase).

          1. The doubanjiang I made is comparably tasty to inexpensive store bought, but it’s only aged ~6 months. I’m hoping it will improve. It definitely has the right flavor, but is a bit sharp and lacking depth in the same way cheaper store bought ones are. I hope you’ll write up your experiments with doubanjiang, especially if you attempt to make one in the Pixian style (without added oil, and aerobic secondary fermentation). The red oil style I made is easier I think.

            I steamed the beans at atmospheric pressure last time. I’ll try 15-20 minutes at pressure next time, and then let them steam off afterward.

            I left feedback on the soy sauce article there. Thank you for sharing it, this is very helpful.

  39. Thanks for the advice! I ordered a few and will run parallel experiments to see what takes to the beans and produces the best enzymes. I may try a. sojae next time.

    One other question — do you have any guidance (numbers, intuition, guesses, etc) on how much gas exchange these molds require? I have some synthetic filter disks for mason jars that filter down to 0.3 microns that I use for mushroom spawn production (mostly vegetative growth; fruiting needs way more air), but I’m concerned they limit air exchange too much for a. oryzae even if I grow a fairly small amount per jar. On the plus side, I could steam the beans right in the jar, and do the inoculation in a still air box to keep everything super clean.

    1. I don’t have any numbers, but what I can say is that Koji grows like wildfire :) much faster than mushroom spawn, so I am not sure if it is going to work well in the way you suggested. Koji produces a lot of heat when it grows, so it is better to have it in a thin mat (max. 3-4 cm thick) in a box. The extreme speed of growth also means that you need not worry too much about contamination too much if you work in a cleanly manner. Koji has much more “elbow technique” than fruiting fungi.

  40. Thank you for taking the time to write this. I’m interested in growing a. oryzae on broad beans to make pixian dou ban jiang (for example, https://chinasichuanfood.com/doubanjiang/).

    Do you have any suggestions with a good strain or strains to try? I’d prefer high protease and low amylase. I’m considering red rice koji, barley koji, soy koji, and soy sauce koji .

    1. Hi Alex!

      Since you are growing the Koji on beans, I would opt for the Soy koji. If you prefer to have as much proetase activity as possible, it might be worth a try to give A. Sojae a chance.

      Kind regards,

  41. Hello Viktor,
    I am not looking to make soy sauce or miso out of my koji, Im trying to experiment with Koji in desserts. With that being said, which strain would I get the sweeter products out of? Thank you!

    1. Hi Erick!

      I would definitely recommend the White Koji in that case. It is a strain that is perfect for amazake, and its aroma is absolutely great. Light rice would be a fitting strain too.

      Kind regards,

  42. Which Koji is Asperligus Orzyae

    1. Hi Surinder,

      every Koji is Aspergillus Oryzae, except Black Koji, A. Luchuensis and A. Sojae.

  43. Thank you for this informative article! I’m wondering if you’ve ever had experience with aspergillus luchuensis. Based on an interview I heard on Cooking Issues it’s supposed to give very fruity notes. The guest, a guy from Noma, described it as tasting like fruit loops on speed. Which sounds amazing to me- I had some early experiences homebrewing at inadvisably warm temperatures (to get that beer faster) and discovered amazing fruit notes coming off the yeast. I would love to learn more about luchuensis and get my hands on it if at all possible.

    Thank you again for your valuable insights.

    1. Hi William,

      I know what you mean about the fruitiness. I do get it in my shoyus quite a lot. Before pressing it it is super fruity, after pressing more mushroomy. In that case the fruitiness is, like in the beer, due to the yeasts producing various esters.
      I have gotten a few requests for A. luchuensis, and I am going to contact my supplier to ask if they have it.
      Meanwhile, I found that the white Koji on pearl barley smells wonderfully flowery :)
      I will let you know once luchuensis is available!

      Kind regards,

  44. Hello, thank you for sharing your knowledge about Koji! I am making my own rice wine and have been using shop bought Miyako Koji, but wanted to experiment with something different. Which koji would you recommend, and would I be able to use it in the same way? In other words do I just add it to the cooked rice (and water etc), or do I need to use the koji spores to make rice koji first? Thanks!


    1. Hi Lan,

      I’d try either the White Koji or the Light Rice Koji.
      You will have to grow the fungus on the rice first!

      Finished Koji rice will be available by April 2019 =)

  45. To age miso like a white variety, what wooden containers are suitable?
    Are old recycled white wine barrels suitable, made from French oak?

    Also if I were to make wooden trays for koji growth what are suitable wood varieties

    1. Hi Mark,

      First off, I have no experience with wine barrels. Does the wood soak up a lot of moisture? If you were to age your miso in a barrel and the wood soaks up a lot of moisture you run into the danger of moldy miso I think.
      That being said, in Japan they traditionally age miso in wooden barrels. So it is definitely possible!

      For my trays I used spruce, as it is widely available around here. In Japan they use cedar. Any soft wood will do.

  46. You say that for sake “you are best off buying two strains”. Do you mean two packets of one strain, namely Light Rice Koji?

    1. Hi Mark,

      I meant that you will need two different strains if you are going to make amazake and soy sauce, i.e. you need light rice Koji spores and soy sauce Koji spores.

  47. Hi Julius,
    yes, I do.

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