[2025] Kuromame Tea - Benefits, Side Effects and Nutrition Facts (2025)

The author of this article is not a doctor. If you need a medical opinion, please consult a medical doctor. This article is for entertainment purposes only.

Kuromame tea, also known as black soybean tea, is a traditional Japanese herbal tea made by roasting black soybeans and steeping them in hot water. Unlike regular green or black teas, kuromame tea is naturally caffeine-free, making it an excellent choice for those who want a warm, flavorful drink without the stimulating effects of caffeine.

It is believed to promote heart health, weight management, and anti-aging. Additionally, this bean tea has been used in Japanese culture for centuries as a functional beverage that supports overall well-being.

In this article, we’ll explore everything you need to know about this tea, including:

• Its nutritional profile and how it compares to other teas
• The health benefits backed by research
• Potential side effects and precautions
• The best ways to prepare and enjoy kuromame tea
• A buying guide to help you find the best-quality black soybean tea

Let’s dive into what makes this unique bean tea so special.

What is Kuromame Tea?

Also called black soybean tea, it is a traditional Japanese herbal tea made by roasting whole black soybeans and steeping them in hot water. The word “kuromame” (黒豆) literally means “black bean” in Japanese.

Origins and Cultural Significance

• This tea has long been consumed in Japan and other East Asian countries, valued for its health benefits and mild, naturally sweet flavor.
• It is commonly enjoyed during the New Year celebrations in Japan, as black soybeans are believed to bring good fortune and longevity.
• In traditional Japanese medicine, black soybeans are used for improving circulation, detoxifying the body, and supporting kidney health.

How is Kuromame Tea Made?

1. Black soybeans are carefully roasted to enhance their flavor and aroma. The roasting process gives kuromame tea a toasty, nutty, and slightly sweet taste, which makes it enjoyable even without added sweeteners.
2. The roasted beans are then steeped in hot water to create a flavorful infusion.
3. The brewed tea is a deep amber color with a smooth, slightly sweet taste.
4. The beans can also be eaten after brewing, making this a zero-waste tea!

Nutritional Profile of Kuromame Tea

Below is the nutrition facts table for Kuromame Tea per 100 ml for both hot and cold brews, with % Daily Values (%DV):

Cold brew values are lower due to reduced extraction. Percent Daily Values are based on a 2,000  kcal diet.

Here’s a breakdown of its nutritional components:

Rich in Antioxidants (Anthocyanins & Polyphenols)

• This tea is high in anthocyanins, the same antioxidant that gives blueberries and black rice their deep color.
• Anthocyanins help neutralize free radicals, reducing oxidative stress and supporting cell health.
• The tea also contains polyphenols, which have anti-inflammatory and heart-protective properties.

Isoflavones – Plant-Based Compounds for Hormonal Balance

• Black soybeans are rich in isoflavones, plant compounds that mimic estrogen in the body.
• Isoflavones can help with menopause symptoms, bone health, and heart health.

High-Quality Protein and Fiber

• Black soybeans are a plant-based protein source, making this tea a good addition to a high-protein diet.
• The tea also provides soluble fiber, which supports gut health and digestion.

Naturally Low in Calories

• A cup of this tea contains almost zero calories, making it an ideal weight-friendly beverage.

Health Benefits of Kuromame Tea

Rich in Antioxidants and Anti-Aging Benefits

• The anthocyanins in this tea help protect cells from oxidative damage, which contributes to aging and disease.
• Regular consumption may help maintain youthful skin, prevent wrinkles, and reduce age-related diseases.

Supports Heart Health

• Isoflavones and polyphenols in black soybeans help reduce bad cholesterol (LDL) and improve blood circulation.

Aids in Weight Loss and Metabolism Boost

• Low-calorie and fiber-rich, kuromame tea helps curb appetite and support healthy metabolism.
• Drinking it regularly may assist with fat metabolism and weight control [study].

Regulates Blood Sugar and Supports Diabetes Management

• The tea helps slow down sugar absorption, preventing blood sugar spikes [study].
• Isoflavones contribute to better insulin sensitivity, making this tea beneficial for diabetics.

Supports Kidney and Liver Function

• Has a mild diuretic effect, promoting toxin elimination through urine.
• May protect liver cells from damage caused by oxidative stress.

Reduces Inflammation and Supports Joint Health

• Anti-inflammatory properties make it beneficial for conditions like arthritis.
• May help reduce joint pain and stiffness with regular consumption.

Possible Side Effects of Kuromame Tea

While kuromame tea is generally safe and packed with health benefits, it is essential to be aware of potential side effects and precautions, especially for individuals with specific health conditions.

Soy Allergy and Sensitivities

• Kuromame tea is made from black soybeans, which means it contains soy proteins that can trigger allergic reactions in some individuals.
• Common symptoms of a soy allergy include hives, swelling, digestive issues, or difficulty breathing.
• If you have a known soy allergy or sensitivity, it’s best to avoid black soybean tea and consult a doctor before trying it.

Effects on Hormonal Balance (Isoflavones & Estrogen-Like Activity)

• Kuromame tea is rich in isoflavones, which are plant-based compounds that mimic estrogen in the body.
• While isoflavones can provide hormonal support, excessive intake may not be suitable for individuals with hormone-sensitive conditions, such as:
  • Breast cancer or ovarian cancer (estrogen-positive cases)
  • Polycystic ovary syndrome (PCOS)
  • Endometriosis
• If you have a hormone-related health condition, consult your healthcare provider before consuming black soybean tea regularly.

Impact on Thyroid Function

• Soy isoflavones may interfere with iodine absorption, which is crucial for thyroid hormone production.
• In people with hypothyroidism or thyroid disorders, excessive consumption of soy-based products, including bean tea, may impact thyroid function over time.
• If you have a thyroid condition, moderate your intake of kuromame tea and ensure you get enough iodine-rich foods in your diet.

Possible Interactions with Medications

• Black soybean tea may interact with certain medications, particularly:
  • Blood thinners (e.g., Warfarin) – Isoflavones in soy may have mild blood-thinning properties, potentially increasing the risk of bleeding when combined with anticoagulants.
  • Diabetes medications – Kuromame tea may help regulate blood sugar, but consuming it alongside diabetes medication might lower blood sugar too much (hypoglycemia).
  • Hormonal therapy drugs – Since isoflavones affect estrogen levels, those on hormone therapy should consult their doctor before consuming black soybean tea regularly.

Digestive Sensitivity & Bloating

• Some individuals may experience mild digestive discomfort, such as bloating or gas, due to the fiber content in black soybeans.
• Drinking kuromame tea in moderation and staying hydrated can help minimize digestive issues.

How to Consume Kuromame Tea Safely

• Start with small amounts (1 cup per day) and observe how your body reacts.
• If you have a medical condition or take prescription medications, consult a doctor before adding kuromame tea to your routine.
• Stick to moderate consumption (1-2 cups per day) to maximize health benefits while minimizing risks.

How to Make Kuromame Tea

Traditional Kuromame Tea Recipe (Hot Brew Method)

The classic way to prepare kuromame tea involves roasting black soybeans and steeping them in hot water to extract their rich, nutty flavor.

Ingredients:

• 1-2 tablespoons of roasted black soybeans (whole)
• 1-2 cups of hot water

Instructions:

1. Roast the black soybeans (if not pre-roasted).
   • Heat a dry pan over medium heat and roast the soybeans for about 5-10 minutes, stirring occasionally.
   • The beans are ready when they turn dark brown and emit a nutty aroma.
2. Steep the tea.
   • Place the roasted black soybeans into a teapot or mug.
   • Pour hot water (around 90°C / 194°F) over the beans.
   • Let the tea steep for 5-10 minutes, depending on your desired strength.
3. Drink and enjoy.
   • The tea will have a light brown to amber hue with a nutty, slightly sweet taste.
   • You can eat the softened soybeans after brewing or use them in other recipes.

Cold Brew Kuromame Tea (Iced Bean Tea)

A refreshing summer version of black soybean tea, cold brewing preserves the delicate flavors while reducing bitterness.

Ingredients:

• 2 tablespoons of roasted black soybeans
• 500ml (2 cups) of cold water

Instructions:

1. Place the roasted black soybeans in a pitcher or bottle.
2. Add cold water and let the mixture steep overnight (8-12 hours) in the refrigerator.
3. Strain before serving and enjoy over ice cubes.

Creative Recipes

Kuromame Latte (Black Soybean Tea Latte)

Ingredients:

• 1 cup of hot brewed kuromame tea
• ½ cup of oat milk or almond milk
• 1 teaspoon of honey or maple syrup

Instructions:

1. Brew a strong cup of kuromame tea and strain out the beans.
2. Heat the milk separately and froth it using a milk frother or whisk.
3. Pour the frothed milk over the tea and sweeten as desired.

Kuromame Tea Smoothie

A nutrient-packed smoothie that combines the antioxidant benefits of black soybean tea with fruits.

Ingredients:

• ½ cup of brewed and cooled kuromame tea
• ½ frozen banana
• ½ cup of yogurt or plant-based yogurt
• 1 teaspoon of chia seeds
• 1 teaspoon of honey

Instructions:

1. Blend all ingredients until smooth.
2. Serve immediately as a refreshing breakfast drink.

Kuromame-Infused Rice

A unique way to enhance Japanese rice dishes with kuromame tea’s nutty essence.

Ingredients:

• 1 cup of white or brown rice
• 1 cup of brewed kuromame tea
• 1 cup of water
• A pinch of salt

Instructions:

1. Cook the rice using a mix of kuromame tea and water instead of plain water.
2. Let it steam and absorb the tea’s rich aroma and nutrients.

Kuromame Tea Jelly

Ingredients:

• 1 cup of brewed kuromame tea
• 1 teaspoon of agar powder or gelatin
• 1 tablespoon of honey or sugar

Instructions:

1. Heat kuromame tea in a pot and dissolve agar powder.
2. Pour into molds and refrigerate until set.

This is a great low-calorie dessert with a subtle, earthy sweetness!

Buying Guide

Where to Buy Kuromame Tea?

You can find black soybean tea in:

• Japanese specialty stores
• Asian grocery stores
• Online marketplaces (Amazon, Japanese tea shops, specialty tea brands)

For the best quality, opt for organic and non-GMO kuromame tea.

What to Look for When Buying Kuromame Tea?

• Whole roasted black soybeans: Ensure the beans are whole and evenly roasted.
• No added flavors or preservatives: Pure kuromame tea should contain only black soybeans.
• Deep, nutty aroma: Fresh kuromame tea has a strong roasted scent.

Best Kuromame Tea Brands

Some trusted brands include:

• Hokkaido-grown kuromame tea (considered premium quality)
• Organic Japanese brands (often labeled as 無農薬, meaning pesticide-free)

Checking customer reviews and certifications ensures you get the best product.

Proper Storage Tips

• Keep in an airtight container to maintain freshness.
• Store in a cool, dry place away from moisture and sunlight.
• Use within 6-12 months for optimal flavor.

Conclusion

With its high levels of antioxidants, isoflavones, and minerals, this bean tea supports weight management, blood sugar regulation, and inflammation reduction. Whether you enjoy it as a hot brew, iced tea, or in creative recipes, kuromame tea offers both flavor and wellness.

Although generally safe, individuals with soy allergies, thyroid conditions, or hormone-related concerns should consume it in moderation.

If you’re looking for a delicious and functional tea with a nutty, roasted flavor, kuromame tea is worth adding to your daily routine.

Have you tried this tea? Share your experiences and any additional tips in the comments below – and feel free to ask any question about it. And subscribe to the Heal with Tea Newsletter for more (herbal) teas.