Miso Recipe

Miso is traditionally a paste made from soybeans, salt, and rice koji. The rice koji is inoculated with the fungus, Aspergillus oryzae. This fungus is needed to ferment the soybeans and turn them into miso.

Making your own miso paste may seem daunting, but the hardest part is waiting for it to finish fermenting. The process takes 3-6 months or longer. For this recipe, I used dried rice koji which I purchased at a local homebrew shop. You can make your own rice koji, which will give you more value for your money. Just note that the koji making process takes 2-4 days in itself.

What are the different types of miso?

The three main types of miso are: Shiro miso, aka miso, and awase miso.

Shiro miso, or white miso, is fermented for the shortest period of time and has less salt in it than aka miso. It has a sweeter and milder flavour which makes it suited to lighter tasting dishes like salad dressings and soups.

Aka miso, or red miso, usually contains a higher proportion of salt and is fermented for a longer period of time. It’s deeper flavour makes it better suited for heartier soups, stews, and meat marinades.

Awase miso is a mixture of the shiro and aka miso pastes. In terms of flavour profile, it sits between the two other pastes, and is very versatile.

What is Rice Koji?

Miso is traditionally made with rice koji. Rice koji is made by steaming rice and then inoculating it with koji starter powder. This powder is made of spores of Aspergillus oryzae. This fungi is used to convert starches to sugars, and proteins to amino acids. Aspergillus oryzae can be used on other grains such as barley, wheat, or pasta, just to name a few. Similarly, you can make miso with other legumes such as split peas, chickpeas, lentils, or blackpeas. The same principles can be used to make miso with different ingredients, so feel free to go crazy and be creative.

Why do we put weights on the miso?

We put the miso in a container that is at least twice as big as the miso paste we have made so that there is enough room to place weights on top of the paste. The weights help to keep the miso in an anaerobic (oxygen-free) environment which is ideal for fermentation. As well, it prevents surface molds from forming on the miso.

Home-Made Miso Method

Step 1

Rinse the dried soybeans well and place in a large bowl. Cover with 500mL of water (2 cups), and leave overnight on the counter. After 18-24 hours have passed, drain the soybeans. They should have doubled in size.

Step 2

Cook soybeans by placing them in a pressure cooker with the remaining 500mL of water (2 cups). If using an Instant Pot, set timer for 20 minutes at high pressure. Let the pressure vent out naturally, otherwise you will get a lot of bean juice steam on your kitchen counters. Alternatively, you can boil the beans and water on the stovetop for 45 minutes or until the beans are tender but not have fallen apart.

Step 3

Meanwhile, clean your wide-mouthed glass jar or crock with hot soapy water. Turn upside down and leave to air dry.

Step 4

When the beans are cooked, drain them. Reserve 125mL (1/2 cup) of bean juice liquid for later. Note: Use the beans quickly after cooking to prevent unwanted bacterial growth. As well, the cooled bean liquid tends to sour quickly.

Step 5

For a smoother consistency, you can mash the beans with a food processor. For a coarser consistency, you can use a potato masher or your hands. Make sure to wear gloves if you are using your hands to mash the soybeans.

Step 6

Soybeans should be at room temperature or at least less than 40°C before mixing other ingredients in. In a large clean bowl with gloved hands, mix the mashed soybeans with 350 grams of dried rice koji and 85 grams of salt and 3 tablespoons of miso paste (optional).

Step 7

Add 2 tablespoons of the reserved bean liquid to create a looser paste, and to help rehydrate the rice koji. While you don’t want too much water in the miso as it increases the chances of unwanted microbial growth, feel free to add more bean liquid to create a looser paste.

Step 8

Pack the miso paste into small balls that are 1-2 inches in diameter. This will help to ensure that when packed into the jar, the miso has no large air pockets in it. We want the miso to be in an anaerobic (oxygen-free) environment.

Step 9

Dip a paper towel in the neutral alcohol and use it to wipe the inside of your container. Pack the miso paste balls into the container, pressing down to ensure that there are no air pockets.

Step 10

Put the container on top of parchment paper and use a pen to trace the outline of the container. Cut out the parchment paper and place in the container, pressing it to the top of the miso paste.

Step 11

There will be a gap between the container wall and the edge of the parchment paper where the miso paste is exposed. Sprinkle coarse salt on this exposed miso paste.

Step 12

Use a clean paper towel dipped in alcohol to wipe off any excess miso paste that is above the parchment paper in the container.

Step 13

Now, you’ll need to place something heavy on top of the miso paste. Fill an empty bag with salt or rocks. Tie it up and place it in the container directly on top of the miso paste.

Step 14

If the container you are using is glass, place the container in a bag so that sunlight cannot penetrate it. Close the lid of the container. Make sure to label the container with the date so that you can tell how old the miso paste is. Set aside.

Step 15

Check the miso paste in 3 months. Remove the weight and see if there is any brown liquid on top of it. This liquid is called “tamari”. This liquid byproduct of fermentation has a nice umami flavour which you can use as a seasoning in your cooking. If you don’t see any dark liquid forming on top of the miso paste, put something heavier on top. The weight on top is needed to keep the environment anaerobic for the miso.

Step 16

Leave the miso for another 3 months and taste. The rice koji should have softened and the colour should have darkened. If the miso hasn’t developed much of a flavour, leave it to ferment for another 3 months and check again. When you are happy with your miso, place it in the fridge to keep long term.

Other recipes you might like:

• Fermented Pineapple Salsa Recipe
• Sauerkraut Recipe