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  • Writer's pictureFoodiesan

An Ode to Koji

There is a miracle. Its name is Koji. It has been called the National Mold of Japan. It is the transformative catalyst for the manufacture of miso, soy sauce, rice vinegars and sake. I never even heard of it until I started coming across it during my research on lacto-fermentation.


And now I can’t get enough of it.


Technically, koji is known as Aspergillus oryzae, or A. oryzae for short. And Wikipedia reports that “the domestication of A. oryzae occurred at least 2000 years ago,[2] “ but with a name like that, it is no wonder that the Western world never picked it up. Besides, we have a thing about spores. But in Japan, koji has been refined over the centuries by Japanese manufacturers. Celebrity chef, David Chang started popularizing it in the US and Europe, it is now being discovered by food geeks such as me for everyday use.


Believe me, there is almost nothing I can think of that can more deliciously transform a just-okay dish into something to swoon over. I am not exaggerating. Well, maybe a little bit.


Here’s how it works:


1. Koji is sprinkled on moist or cooked rice (or another grain, such as barley).

2. The mold and grain are incubated.

3. The mold invades the grain and breaks the starches into sugars and amino acids that create an incredible umami flavored agent.


You can make koji yourself at home, with the right equipment. And I have all the ingredients to do it myself, but I haven’t done it yet. It seems like a lot of trouble. I just purchased a marvelous book called The Noma Guide to Fermentation, which explains how to make koji in great detail. Noma, incidentally, has been named the best restaurant in the world for four years. The only problem is that it’s in Copenhagen. In January, I will be attempting this process with my friends Yuka Mullen and Akiko Olsen. Stay tuned.


But you can also just buy it. It comes in different forms. You can purchase from Amazon.com the dry, inoculated rice cakes and concoct your own Shio Koji sauce with salt and distilled water. The dry form looks like this:


Dried Koji

You can also purchase “shio koji” sauce either from Amazon or my favorite Asian food market, Uwajimaya. This is what I would recommend doing, because this is the easiest path to Nirvana. Shio Koji looks like this:

The amazing thing is that you don’t really even need a recipe to produce astounding results.


Example #1: We had about 20 guests coming for dinner unexpectedly, so I just took several pounds of the salmon filets we had in the freezer, massaged a small handful of the sauce into the flesh and let it set for a couple of hours. We threw it on the grill. It knocked our socks off.


Example #2: Knowing that shio koji is a great tenderizer, I massaged a couple tablespoons into two tri-tip roasts and marinated it for a couple of days. After we grilled it, we could not believe how tender and flavorful beef could be.


Example #3: This is only a tad more complicated, but I put a combination of ¼ cup of shio koji, grated ginger, a sprinkle of rice wine vinegar and a minced thai pepper with ¾ inch chunks of an english cucumber, an equal amount of daikon and thinly sliced carrots. Within two hours, we had a fabulous pickle salad.

Instant Daikon, Cucumber and Carrot Shio Koji Pickles

Now that I’ve discovered shio koji, I am putting small amounts into all kinds of things. Yesterday I threw a couple tablespoons into the marinade for a batch of miso chicken we were grilling. Best ever! I snuck (is that a real verb?) a tablespoon into some bolognaise sauce I was making. It took my breath away!

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