learn about miso paste

Do you know what Miso Paste is? Miso Paste (みそ, 味噌) is a traditional Japanese fermented seasoning. Globally, it’s drawing attention as a healthy food and now it’s easy to find miso paste options all over the world.

In this page, you’ll get a better understanding of the information written on Miso Paste’s package and what you should compare when choosing what to buy at the market.

Miso paste varies widely depending on the manufacturer, so it is very difficult to judge which one can be your favorite. I hope that this knowledge of analyzing English or Japanese information written on the package, will help you to decide what your preference is.

Table of Contents

Categories and Tastes of Miso Pastes

3 miso pastes

What’s the difference between Red Miso Paste and White Miso Paste? The answer is in this section.

Whether it’s “Red” or “White”, Miso Paste looks like brown paste. Its raw materials consist of “soybean”, “salt”, “water” and “koji”.

What is Koji?

The type and the amount of koji that is used to make Japanese miso paste, and the aging periods vary. They depend on the traditions and preferences in each area of Japan.

In short, there are numerous kinds of Miso Pastes in japan, and all of them taste different.

Coming up, let’s learn about the 3 main categories of Miso Paste.

Red Miso Paste (赤味噌、赤みそ)

red miso paste

“赤” is a kanji that means “red”. Red Miso Paste (赤味噌、赤みそ) that tends to be frequently found is the one that is made by adding Rice-Koji, and the color is darker brown. Sometimes Red Miso Paste which is made with Soybean-Koji is sold too, and it is deep dark reddish brown.

In the manufacturing process of red miso paste, the raw material soybeans are steamed, not boiled like soybeans for white miso paste. That’s why, red miso paste is usually more nutritious, when compared to white miso paste.

And also, after mixing koji, red miso paste is aged longer than white miso paste.

The flavor is stronger and richer than white miso paste. Depending on the manufacturer, red miso paste may contain more sodium than white miso paste.

White Miso Paste (白味噌、白みそ)

white miso paste

“白” is a kanji that means “white”. White Miso Paste (白味噌、白みそ) which tends to be frequently found is the one made with Rice-Koji, and the color is lighter brown.

In the manufacturing process of white miso paste, the raw material soybeans are boiled, not steamed like soybeans for red miso paste. That’s why, white miso paste is usually a little less nutritious than red miso paste.

And also, after mixing koji, white miso paste is aged shorter than red miso paste. Because of that, we usually see more pieces of soybean grain remained in white miso paste.

The flavor is lighter than red miso paste and you can enjoy the soybeans natural sweetness. Depending on the manufacturer, white miso paste may contain less sodium than red miso paste.

Awase Miso Paste (合わせ味噌、合わせみそ)

awase miso paste

Awase Miso Paste is the mixture of two or more miso pastes. The Japanese word “awase” here, means “combined” or “mixed” and you might see on the package “合わせ”, “合せ” or “あわせ” in Japanese.

Depending on the manufacturer, the composition is different. You can enjoy the balanced flavor of multiple miso pastes.

The Information You find on the Package of Miso Pastes

The front of the package, the ingredients list, the Nutrition Facts, What do you find on the container of the miso pastes? There’s a great deal of useful information to select the miso paste your looking for. Let’s go through one by one.

The Ingredients of the Miso Paste

As I mentioned in the previous chapter, the raw materials of miso are below.

  • soybean
  • salt
  • water
  • koji (rice, barley or soybean)

This means, anything other than these are additives. In other words, if you see only those ingredients, that miso paste is pure and unseasoned.

The common additives for miso pastes are the alcohol(or ethyl alcohol) to disinfect unwanted bacteria and to stop fermentation, and the seasonings to improve the taste.

Example of Product used Alcohol for Disinfection
Example of Product used Alcohol for Disinfection

Whether “DASHI” is Included in the Miso Paste

If you are making miso soup, THIS is very important. Because, depending on this, the cooking method of miso soup will change.

Japanese soup stock “Dashi(だし, 出汁)” is the word meaning “broth” in Japanese. The soup stocks used for Japanese Foods are mainly taken from Niboshi (にぼし, 煮干, small dried sardines), Katsuo (かつお, 鰹, bonito), Kombu (こんぶ, 昆布, kelp) etc, but we often see that any of these soup stocks are collectively called as Dashi.

How to make Japanese Dashi soup stock easily?

If there is a notation such as “Contains Dashi” or “Dashi Stock” in the front of the package, or the names which seems to be seaweed or fish in the ingredients list, the miso paste is seasoned.

miso paste contains Dashi stock

Basically, that type of miso paste that contains soup stock, becomes miso soup when you simply dissolve it into hot water.

awase miso label
Example of Product which has mixed Several Kinds of Miso Paste and Dashi Seasonings such as Bonito Powder and Kelp Extract

Are the soybeans used in miso soup production Non-GMO?

Thanks to the strict rules established by The Japan Federation of Miso Manufacturers Cooperatives, all members company’s products are Non-GMO even if you don’t see any mention of it on the bag. However, it doesn’t hurt to choose the product that declares the fact.

Non-GMO means “遺伝子組み換えでない” or “非遺伝子組換え” in Japanese. Possibly you see like “遺伝子組み換え大豆は使っていません” or “遺伝子組み換え大豆不使用” on the package of the miso paste.

Confirm the Amount of Sodium in the Miso Paste

red miso label

Regular miso paste for miso soup, contains about 12% of salt (equivalent to 236.2mg sodium per 1tsp). That’s because it meets traditional manufacturing standards such as the prevention of bad bacterial growth during fermentation.

On the Nutrition Facts, the serving size is different depending on the manufacturer and that seems to be hard to compare. So, in several miso pastes, I calculated the sodium content per 1 tsp(5ml).

1 tsp(5ml) of miso paste is the amount that I need when I make 1 small cup of miso soup.

  • Red Miso Paste(Hikari Miso): 244.4mg
  • White Miso Paste(Hikari Miso): 231.1mg
  • Red Miso Paste(Hanamaruki): 235mg
  • White Miso Paste(Hanamaruki): 235mg
  • Awase Miso Paste contains dashi(Marukome): 276.7mg

How to Calculate the Sodium Content per 1 Teaspoon(5ml)

■ mg*÷■ Tbsp**÷3

*the Amount of Sodium per Serving on the Nutrition Fact
**the Serving Size on the Nutrition Fact

the Examples of Numbers go into the ■ of Tablespoon

1/2 Tbsp = 0.5
2/3 Tbsp = 0.67
3/4 Tbsp = 0.75
1 Tbsp = 1
1 1/3 Tbsps = 1.33
1 1/2 Tbsps = 1.5

the Serving Size: 1 1/3 Tbsps
Sodium: 940mg
940 ÷ 1.33 ÷ 3 = 235.6
This miso paste contains 235.6 mg sodium per Tsp(5ml)

FAQs about Miso Paste

Why is my miso soup so salty and tasteless? Did I pick the wrong miso paste?

In that case, the miso paste doesn’t seem to be the problem, but the soup does. Miso soup is NOT just miso paste dissolved into hot water. You need to dissolve the right amount of miso paste into a GOOD broth.

How to make Japanese Dashi soup stock easily?

Kelp and Niboshi Stock
Making Kelp and Niboshi Broth

Why is the color of all miso pastes different?

The difference of the aging period is the main reason that there is a difference in color. Due to the Maillard reaction, the miso pastes that have aged longer will get deeper color. That also effects the taste and flavor of the miso pastes.

The aging period of white miso is 1 week to 3 months, while the aging period of red miso is from 6 months to 4 years.

What is Koji?

Koji is the culturing of grains for certain microorganisms that are effective for the fermentation of food. There are 3 types of koji to make miso paste which depends on the kind of grain, Rice-Koji, Barley-Koji and Soybean-Koji. (I see some translation of koji “malt” or “yeast” but I can’t agree with that.)

Rice Koji
Rice Koji

What is the best way to preserve miso paste after I open it?

After opening, don’t only close the lid but also place a piece of plastic wrap onto the miso paste directry not to allow it touch the air as little as possible. If your miso paste is in a bag, pull out the air and seal it any way possible (example:large food clip). Then, keep it in the refrigerator.

Keeping it in a freezer is also good idea because miso never becomes hard and you can scoop it up even after you freeze it.

wrap miso

Should I toss away the expired miso paste?

Regular PURE miso paste(a salt content of 12%, contains NO dashi stock) is very resistant to decay. As long as it doesn’t taste weird (no bad bacteria are breeding), it is still edible.

Of course, it is not garenteed that all miso pastes are 100% safe to eat after the expiration date, but it seems unnecessary to be so strict.

I tried eating pure miso paste which I kept refrigerated properly for 1 year after the expiration date, but nothing strange happened. If I’m forced to find a difference, the taste seemed to be a little bit stronger.

miso soup 

How much sodium is reduced in low sodium miso paste?

In Japan, there is the rule that they can label “Low Sodium Miso Paste” on their product when they cut down more than 15% of commonly used salt. However, Low Sodium Miso Paste could be weaker against molds and germs.

Low Sodium is “減塩” in Japanese.

 How to Calculate the Amount of Sodium in the Miso Paste

Related Videos

Learn about Japanese Products


  • Japan Miso Promotion Board(みそ健康づくり委員会)


    *This group is organized by 958 miso paste companies.

  • Japan Federation of Miso Manufacturers Cooperatives(全国味噌工業協同組合連合会)
  • Food Composition Database(食品成分データベース) by MEXT (Ministry of Education, Culture, Sports, Science and Technology)
    *This database was developed by Japanese Ministry of Education, Culture, Sports, Science and Technology, and it is published experimentally.
  • Marukome co.,ltd. (マルコメ株式会社)
  • Hikari Miso Co.,Ltd (ひかり味噌株式会社)
  • Hanamaruki Foods Inc. (ハナマルキ株式会社)