Want to start the new year right? Make a batch of Kuromame for good luck! These sweetened Japanese black beans are really easy to make and you only need 6 ingredients to make them.

Kuromame is an authentic Japanese dish that can be made at home. It’s traditionally eaten for the new year (Osechi Ryori), but you can eat it any time of year! This recipe comes from my mom who learned how to make Kuromame in Japan. The soybeans are black because they’re soaked in sugar water with rusty nails until they turn shiny black and become really sweet. It’s an easy and simple dish to make – just simmer them with sugar and shoyu (soy sauce) until they’re soft!

Sweetened black soybeans served in a small bowl with a pair of chopsticks

It’s time to get cooking!

Today, I’m going to show you how to make Kuromame (sweetened black beans), a popular traditional Japanese new year food.

This delicacy is traditionally served as part of osechi ryori (new year’s feast) as it symbolizes good health for the upcoming year. The taste can be sweet or salty depending on what type of sugar is used – typically white or brown sugar is used to create this dish.

Kuromame simmered black soy beans served in a small shallow bowl.

Sweet Soy black beans (Kuromame): The Lowdown

So what is Kuromame? The literal translation of Kuromame is “black bean.” There are lots of variations of this recipe, but most of them have some sort of combination of sweet and savory flavors. Aside symbolic meanings, the Kuromame black soybeans used in the recipe is a type of soy bean which are packed with protein, fiber, vitamins, minerals and anti-oxidants.

Although these beans are sweet, they are eaten along with all the other main savoury and salty dishes as a nice counterpoint during the New Year’s lunch/dinner, just like the Kuri Kinton (Sweetened Chestnuts & Pureed Sweet Potato).

But, since they are so deliciously sweet, they also make a great snack to eat after New Year’s because there is usually a lot of leftovers.

Why You Will Love this Sweet Black Beans

If you enjoy the combination of sweet and salty flavors in your recipes, then this is the recipe for you. The briny umami flavors combine effortlessly with sugar and enhance the earthy tastes of the black soybeans.

My daughter especially loves Kuromame so my mom always makes them for her whenever she goes back, even if it’s not around New Year’s day. Since I usually only go back every few years, I don’t get to eat Kuromame for a long time because I didn’t think they sold them anywhere in my city so I never thought to look.

But, this year I really wanted to make them for the New Year’s meal, so I went to look for them and just found them at the Japanese shop right near my house. I was so happy because now I can make them whenever and I don’t have to wait years to eat them!

Hopefully, you’ll be able to find Kuromame at a Japanese/Asian grocery store wherever you live and be able to make them too because they’re sweet and so delicious. I hope you enjoy this recipe!

sugar, water in a jug, salt, bicarb soda, soy sauce, black soybeans and rusty nails

Ingredients In Kuromame Recipe

There are just a few simple ingredients in this classic recipe. Here’s a bit more information about what I used, along with any substitutions you can make.

Beans: There really isn’t a good substitution for the soybeans. Any other type of bean will have a different taste and texture. Do not use canned or frozen beans. The flavors infuse in the dried beans as they soak in the Shoyu soy sauce and sugar mixture.
Sugar: For best results, I suggest using white granular sugar. Any other type of sugar will throw the texture of the recipe off.
Soy Sauce: Any type of soy sauce is perfect for this recipe. If you are trying to watch your salt intake, use low-sodium. If you are celiac or follow a gluten-free diet, substitute with coconut aminos.

Where do you get black soybeans?

You should be able to buy black soybeans from your local grocery store. If not, you can always find dried black soybeans online.

How To Make Sweet Japanese Black Beans

Cooking soy black beans is time-consuming, because you need to soak beans overnight. However it is worth every single minute. Here’s a quick overview of the main steps to the recipe. Remember, all of them are in the printable recipe card at the bottom of this post.

Cook The Soy Sauce and Sugar Mixture

Rince black soy beans with cold water and discard bad beans.

The first step is to cook the 1/2 tbsp of soy sauce, 2 cups water, 1/2 cup sugar, 1/4 teaspoon salt and 1/4 teaspoon bicarb soda in a saucepan over medium heat until the sugar is completely dissolved.

a 4 photos collage of sweet kuromame making process

Soak Soybeans Overnight

Then, add the cleaned soybeans in the saucepan with the mixture while the sauce is still hot. Then cover 3-5 rusty iron nails with cheesecloth or muslin cloth and add it to the cooking pot or saucepan. I used a tea bag that you can purchase from shops like Daiso. The reason to add rusty nails in cooking black soybeans is to make the black soybeans into rich really dark black color. It occurs because of a chemical reaction with tannin in the beans and iron oxide in rustic nails.

soy black beans in a pot with a wooden lid on

Boil To Remove Scum

Next, bring the beans to a boil over high heat. This will bring a layer of scum to the surface. When it does, turn the heat to low and use a ladle to take the scum off the top.

You’ll repeat this step by adding more water, boiling it again, and removing more scum.

Simmer On Low Again

Place a drop lid (Otoshibuta) on top of the pot of beans. If you don’t have a dlop lid, you can make it, see this post to read how to make Otoshibuta. Simmer the beans over low heat for another 3-4 hours.

After the beans are soft, you are ready to serve them!

a 4 photo collage of making sweet kuromame

Two Tips to prepare Soy Black Beans

I will share my trick so that your Kuromame turns shiny and plump good looking soybeans with no wrinkles.

1. Add beans into hot shoyu soy sauce and sugar mixture.

2. Add either rusty nails or a fish cast iron. *my cast iron is shape of a chestnut in the photo.

What To Serve With Homemade Kuromame

This is a side dish that is usually served with other traditional New Years’ recipes. I compiled all of my favorite Osechi Ryori recipes into one complete guide. This Osechi Ryori lunch plate has photos, descriptions, and links to my favorite recipes!

My two go-to’s are:

Frequently Asked Questions About Japanese Black Beans

Before I get to the recipe card at the bottom of this post, here are some questions people often have about Kuromame.

Are black beans the same as soy beans?

No, these are not the same as black beans. They are entirely different type of soybean. I used black soybeans in this recipe. Black soybeans are the same thing as white soybeans, except they have a black color seed coat on the outside.

left- soy black beans, and right - is black turtle beans — black soy beans (left), black turtle beans (right)

Can you freeze kuromame?

Yes, you can make this recipe ahead of time and store it in the freezer. It will stay fresh in the freezer for about a month. When you are ready to reheat it, I suggest reheating the beans on the stovetop instead of the microwave.

Do I need to soak the black soybeans?

Yes, you need to soak the black soybeans in the hot soy sauce and sugar mixture. This way they will become soft without getting too wrinkled.

More Osechi Ryori Recipes

If you enjoyed this Kuromame recipe, here are some more Osechi Ryori recipes you might want to try next. They are some of my favorites!

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