How to Make Shiitake Dashi Properly

Shiitake Dashi, which contains a large amount of umami components, not only tastes delicious, but also allows you to enjoy the rich aroma of shiitake mushrooms. Among the dashi broths used in Japanese cuisine, it is one of the easiest to make with minimal effort.

Jump to:

• What is Shiitake Dashi?
• Why use shiitake mushrooms?
• The reason for making dashi with cold water
• Can sliced shiitake mushrooms be used?
• If you want to use shiitake dashi immediately
• Way to enhance the nutritional value of shiitake mushrooms
• How to make Awase Dashi (kombu and shiitake dashi)
• How to extract maximum flavor from shiitake dashi
• Ingredients
• Step-by-step instructions
• Tips on how to make
• Recipe Card

What is Shiitake Dashi?

Shiitake Dashi is a type of dashi broth used in Japan that is extracted from dried shiitake mushrooms when they are rehydrated in water. It doesn't need to be heated and can be made simply by soaking the dried shiitake mushrooms in water. Like kombu dashi, it's a vegan option.

In Japan, shiitake dashi is commonly used to make simmered dishes, soups, and cooked rice dishes. It contains high levels of guanylic acid and glutamic acid, which are umami components that people find tasty, and is one of the classic dashi in Japan, along with Kombu Dashi and Bonito Dashi.

Guanylic acid, the primary component of shiitake dashi, is created through the process of drying fresh shiitake mushrooms. So it is necessary to use dried shiitake mushrooms to make the dashi, not fresh ones. After making dashi, the shiitake mushrooms can be used as an ingredient in cooking.

Why use shiitake mushrooms?

Among various mushroom types, dried shiitake mushrooms are used to make dashi broth due to their high umami component.

In particular, it is known that they contain over 10 times the amount of guanylic acid than other types of mushrooms. This abundance of guanylic acid is the main reason why shiitake mushrooms are used as ingredients for making dashi among mushrooms.

Since guanylic acid is an umami component that is rarely found in other ingredients, just adding a small amount of shiitake dashi to soups can make them taste even better.

The reason for making dashi with cold water

First and foremost, it is important to remember that when making dashi broth from dried shiitake mushrooms, you should not heat them up. You also shouldn't use hot water. I've seen several websites in English about how to make shiitake dashi, but I'm surprised by the amount of misinformation that exists.

When dried shiitake mushrooms are rehydrated, ribonucleic acid (RNA) is extracted during the process, before it is converted to guanylic acid. RNA is most easily extracted in cold water at 41°F (5°C) and is broken down into guanylic acid when heated. If dried shiitake mushrooms are rehydrated with hot water or boiled, it is difficult to extract RNA, and as a result, guanylic acid is hardly produced. Therefore, when making shiitake dashi, it is recommended to rehydrate them in cold water in the refrigerator for a longer period of time.

It is said that the ideal time to rehydrate dried shiitake mushrooms in cold water is 10 hours (depending on the type and thickness of the shiitake mushrooms). While you can obtain dashi with a similar color from mushrooms rehydrated for a few hours and those rehydrated for 10 hours, you will notice that the umami and aroma are different when you taste it. However, if you rehydrate the dried shiitake mushrooms in water for too long, bitter components may be produced, so be sure to remove them within 24 hours.

Can sliced shiitake mushrooms be used?

You can also make shiitake dashi from sliced dried shiitake mushrooms. However, the flavor extraction differs between sliced and whole shiitake mushrooms.

While enough umami components can be extracted from sliced dried shiitake mushrooms in about half the time (around 5 hours) compared to whole ones, the aroma can hardly be extracted. In other words, the aroma is weaker, but it is possible to make shiitake dashi in a shorter time. If you are not fond of the aroma of shiitake mushrooms, using sliced ones may be more suitable for you.

If you want to use shiitake dashi immediately

The best way to make shiitake dashi is by slowly rehydrating dried shiitake mushrooms in cold water. However, if you need to use it immediately, I recommend grinding up dried shiitake mushrooms instead. This way, you can extract the umami flavors of the shiitake mushrooms without losing too much flavor and make a broth. You can also grind up the stems of the shiitake mushrooms, which are usually discarded, and use them as well.

Note that the ground shiitake mushrooms should be heated before consumption. Although rare, consuming uncooked shiitake mushrooms may cause an allergic reaction.

Way to enhance the nutritional value of shiitake mushrooms

If you want to extract more nutrients from shiitake dashi, place dried shiitake mushrooms with their gills facing up in sunlight for about 2 hours before rehydrating them. This will increase the amount of vitamin D2 in the shiitake mushrooms by about ten times. The same applies to fresh shiitake mushrooms as well.

Once generated, vitamin D2 can exist for several months, so it is best to expose shiitake mushrooms to sunlight whenever you have the opportunity. However, this process is not essential since it enhances the nutritional value of shiitake mushrooms without affecting the taste of the shiitake dashi itself.

How to make Awase Dashi (kombu and shiitake dashi)

When making dashi broth with two or more ingredients instead of just one, you can experience a stronger umami flavor due to the synergistic effect.

Another ingredient that is suitable for adding to shiitake dashi is kombu (kelp). You can make Awase Dashi (a combination dashi) with kombu and shiitake mushrooms by adding them to the water at the same time. However, if you soak the kombu in water for more than 10 hours, the water may become cloudy and develop a distinct smell, so be sure to remove it halfway through the process.

Besides kombu, it is also recommended to add dried bonito flakes for more flavor.

How to extract maximum flavor from shiitake dashi

Dried shiitake mushrooms also contain an enzyme called nucleotidase, which breaks down guanylic acid. When nucleotidase is active, the guanylic acid extracted from shiitake mushrooms will disappear. This enzyme is most active at temperatures between 104-140°F (40-60°C). For this reason, it is recommended to heat shiitake dashi quickly over high heat to minimize activation of nucleotidase.

However, if you boil the shiitake dashi, the ribonucleic acid is less likely to convert to guanylic acid, causing a loss of umami. Therefore, the key to extracting maximum flavor is to reduce the heat before boiling.

In other words, by heating the shiitake dashi over high heat at first and reducing the heat to low when bubbles begin to appear, you can warm the shiitake dashi without losing its flavor.

Ingredients

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Step-by-step instructions

🕒 Total 10 hrs

Step 1
Rinse the dried shiitake mushrooms. Put the shiitake mushrooms and water in a bowl, and soak them in the refrigerator for about 10 hours.

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Step 2
Remove the rehydrated shiitake mushrooms and strain the shiitake dashi through a sieve (and paper towels if necessary). The shiitake mushrooms can be used as an ingredient.

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Step 3
When using the shiitake dashi you have made, heat it in a pot over high heat. Once some bubbles begin to appear, reduce the heat to low and simmer slowly at a temperature just below the boiling point. This will allow you to fully enhance the flavor of the shiitake dashi. (For more information, refer to this).

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To Store

You can store it in the refrigerator for up to 3 days.

Tips on how to make

• Rinse the dried shiitake mushrooms before soaking them in water. Dried shiitake mushrooms often have dust and sawdust attached to them during their production process. Don't worry, the umami component won't be lost even after they are cleaned.
• Soak the dried shiitake mushrooms in cold water. The ideal temperature to extract the umami component of dried shiitake mushrooms is 41°F (5°C). If water temperature exceeds 77°F (25°C), the bitter component is also released, so it is recommended to rehydrate dried shiitake mushrooms in a refrigerator.
• Dried shiitake mushrooms should be soaked in water that is about 20 times their weight. If there is not enough water, the dried shiitake mushrooms may not rehydrate properly.
• Slowly rehydrate the dried shiitake mushrooms in water for about 10 hours. There will be a noticeable difference in aroma and flavor between a few hours and 10 hours of soaking.

Recipe Card