Here’s an embarrassing confession.

Until I was past 50, I almost exclusively drank instant miso soup.

Hot water, thirty seconds. Convenient, and the taste isn’t bad. It was a habit I picked up during a stretch when my wife was ill and couldn’t cook, and it just… stuck.

”Since I’m At It, I Should Make It Properly”

As I started getting interested in fermented foods, I thought, “At least let me make the miso soup from scratch.”

I’d been overthinking it at first, but when I actually tried, it was surprisingly simple. Take some kombu kelp and katsuobushi (dried bonito flakes) to make dashi broth, then dissolve the miso in. That’s it.

The first bowl I made — one sip in — I honestly thought, “This is completely different.” The fragrance of the dashi, the depth of the miso — nothing like instant. Instant isn’t bad, but I hadn’t realized how different they could be.

I Stood in Front of the Miso Shelf for Fifteen Minutes

After that, I started paying attention to the miso section at the supermarket.

One evening after work, I stopped by and stood in front of the miso display.

I was surprised by how many varieties there were. Shinshu miso, Sendai miso, mugi (barley) miso, hatcho miso, white miso, blended miso. Prices ranged from around 200 yen to over 1,000 yen. The packaging was covered with phrases like “domestic soybeans,” “naturally brewed,” “no additives.”

What’s “naturally brewed,” anyway?

When I looked it up, I found that “naturally brewed” (tennen jozo) means miso that’s fermented and aged slowly in its natural environment, without using heat management to speed things up. The alternative — soybeans and koji (the mold used for fermentation) treated with heat and produced quickly — is called “rapid brewing.”

Some naturally brewed miso takes over a year to make.

A Strange Sense of Wonder at the Idea of “One Year”

One year. Food that changes over the course of a year.

Bacteria slowly, slowly break down soybeans, salt, and koji (the mold culture) and build up umami along the way. Nothing is rushed. You just wait.

I found something deeply rich about that idea.

It’s the exact opposite of the efficiency-and-speed-first logic of modern food production.

A Wooden Barrel Arrived from a Miso Shop in Fukui, Founded in 1914

While I was trying naturally brewed miso from the supermarket and reading about it, an idea came to me.

“Could I make it myself?”

After some research, I found a shop in Fukui Prefecture that has continued making miso using traditional methods. They sell kits with a wooden barrel, soybeans, and salted koji, so you can make your own homemade miso.

I took the plunge and placed an order. That was in February 2024.

When the wooden barrel arrived, I laughed a little at myself — “Are you really doing this?” I cooked the soybeans, mixed them with the salted koji, packed them into the barrel. Carefully pressed out the air, placed a weight on top, and then just… waited.

Miso Soup Made with Miso I Made Myself

About a year after packing that barrel, when I opened it, the aroma was unlike any miso I’d ever smelled.

The sweetness of the soybeans, a deep fermentation fragrance. Sure, there’s some bias since I made it myself — but it was genuinely delicious.

Now I make miso soup every morning with that homemade miso from the wooden barrel. From instant soup to naturally brewed store miso to miso I packed myself — I’ve come a surprisingly long way.

“Fermentation — time is what creates the flavor,” I now feel that in my bones.

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Next time: Three months of eating fermented foods. Has my body changed? An honest report.

※ This article is based on personal experience and publicly available information. It is not intended to diagnose, treat, or prevent any disease. If you have health concerns, please consult a doctor or registered dietitian. See our Disclaimer.