How Is Traditional Japanese Miso Made? A Guide to Authentic Fermented Soybean Paste

How Is Traditional Japanese Miso Made? : A Guide to Authentic Fermented Soybean Paste

Answer

Miso is a traditional Japanese fermented paste made from soybeans, koji, and salt.
Through months (sometimes years) of fermentation, natural enzymes create deep umami, aroma, and complexity.

Curious which miso suits your cooking style?
→ Explore Our Japanese Miso Collection


What Is Miso?

Miso is a traditional Japanese fermented soybean paste and one of Japan’s most essential seasonings.
It is made from just three core ingredients: soybeans, koji (cultured grains inoculated with koji starter), and salt.

There are four main types of miso:

・Rice Miso (Kome Miso) – Made with rice koji, the most common variety

・Barley Miso (Mugi Miso) – Made with barley koji, often slightly sweet and rustic

・Soybean Miso (Mame Miso) – Made only from soybeans, deeply rich and intense

・Blended Miso (Awase Miso) – A mix of different miso types

The type of koji used determines the flavor profile, sweetness, aroma, and color of the final miso.

How Miso Is Made

Below is the traditional process for rice, barley, and soybeans miso.
Rice miso is the most widely (about 80%) produced variety in Japan.


Soybeans (Common Base)
Steam / Boil
↓
Rice Miso
Steam Rice
↓
Add Koji Starter
↓
Rice Koji
↓
Mix with Soybeans + Salt + Water
Barley Miso
Steam Barley
↓
Add Koji Starter
↓
Barley Koji
↓
Mix with Soybeans + Salt + Water

↓
Fermentation & Aging
↓
Packaging

Mame Miso (Soybean Miso)
Soybeans
↓
Steam / Boil
↓
Roast (Optional)
Inoculate with Koji Starter
↓
Create Soybean Koji
↓
Mix
↓
Add Salt + Water
↓
Long Fermentation & Aging
↓
Packaging

How to Use Miso (Beyond Miso Soup)

Miso is incredibly versatile — not just for traditional Japanese dishes.

Here are ways to use miso in Western cooking:

  • Add to salad dressings for savory depth

  • Mix into butter or cream sauces for pasta

  • Use in glazes for roasted vegetables

  • Add to marinades for chicken, pork, or fish

  • Stir into mashed potatoes for a subtle umami boost

  • Blend into caramel or desserts for sweet-savory contrast

A small spoonful can transform everyday cooking.

Today’s Takeaway

Miso is more than a seasoning — it is a living fermented food shaped by time, craftsmanship, and nature’s enzymes.
From traditional soup to modern Western cuisine, miso brings depth and balance to your kitchen.

References

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Explore Authentic Japanese Miso

If you’re ready to experience real Japanese fermentation, browse our carefully selected miso collection — crafted by traditional producers and shipped directly from Japan.

→ Explore Our Japanese Miso Collection

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