Are Black Sesame Naturally Black? The Surprising Science Behind Their Dark Hue

December 7, 2025 •

4 min read

Sesame seeds are one of the oldest cultivated oilseed crops in the world, with a history spanning thousands of years. A common query is whether the rich, dark shade of black sesame seeds is their natural color, or if they are dyed. The compelling answer is that true black sesame seeds are, in fact, naturally black.

Quick Summary

Authentic black sesame seeds are naturally dark due to melanin pigment in their intact outer seed coat, unlike white sesame seeds which are typically hulled. Different seed colors arise from different plant varieties.

Key Points

Natural Pigmentation: Black sesame seeds are naturally black due to melanin concentrated in their outer seed coat, a pigment also found in humans.
Unhulled vs. Hulled: The primary difference between black and white sesame seeds is that black ones retain their outer hull, while white ones have it removed.
Nutritional Density: The intact hull gives black sesame seeds a higher nutritional value, including more calcium, iron, and antioxidants like lignans, compared to hulled white seeds.
Flavor Profile: Black sesame seeds have a more intense, nutty, and slightly bitter flavor, along with a crunchier texture, due to the presence of the hull.
Dye Detection: You can spot fake dyed sesame seeds by soaking them in cold water; dyed seeds will release color immediately, while natural seeds will not.
Plant Varieties: Black and white sesame seeds come from the same species of plant (Sesamum indicum), but are different cultivars that produce distinct seed colors.

The Melanin Magic: What Gives Black Sesame Its Color?

Yes, black sesame seeds are naturally black, and the secret lies in their seed coat. While white sesame seeds are harvested and processed to remove their outer hull, black sesame seeds are typically left unhulled. The dark pigment responsible for their distinctive color is called melanin, the same pigment that colors human skin and hair. Scientific studies have successfully isolated and characterized melanin from black sesame seeds, confirming its natural origin and chemical properties.

This melanin is concentrated in the seed's hull, and its presence not only dictates the seed's color but also contributes to its overall nutritional profile. The intact hull provides a richer source of antioxidants and minerals compared to hulled white sesame seeds.

The Difference Between Black and White Sesame Seeds

Many people are surprised to learn that black and white sesame seeds come from the same plant species, Sesamum indicum. The key difference is the variety of the plant (cultivar) and how the seeds are processed.

The Hull Factor

Black Sesame: These seeds are sold unhulled, meaning they retain their thin, edible, dark outer shell. This gives them a more intense, nutty, and slightly bitter flavor, along with a satisfying crunch.
White Sesame: These are typically hulled. The removal of the hull reveals the creamy white inner kernel, resulting in a milder, sweeter flavor and a softer texture.

Flavor and Nutritional Variations

The presence of the hull in black sesame seeds has a significant impact beyond just color and texture. The hull is rich in dietary fiber, lignans (powerful antioxidants), calcium, and iron. Therefore, black sesame seeds often have a slightly superior nutritional profile compared to their hulled white counterparts. The intense, earthy flavor of black sesame makes it a common ingredient in many Asian desserts and savory dishes where its taste can stand out, while the milder flavor of white sesame is more versatile for a range of recipes.

Natural vs. Dyed Black Sesame: How to Spot a Fake

Unfortunately, the natural appearance of black sesame seeds is sometimes mimicked by dyeing cheaper white seeds. However, it is relatively easy to tell the difference with a simple test.

Steps to identify dyed sesame seeds:

Soak in cold water: Place a small amount of black sesame seeds in a glass of cold water. Natural seeds will not bleed color immediately. Dyed seeds will quickly tint the water with a dark, almost black color.
Look for color change over time: After soaking natural seeds for a while, the water may take on a faint, reddish-brownish tinge, which is the natural pigment slowly leaching out. This is not an indication of dye.
Inspect the inside: Cut a black sesame seed in half. The endosperm (the inside part) should be white or off-white. If the inside is also black, it is likely that the seed has been dyed.
Check for stains: Rub a handful of the seeds between your palms. If they leave behind a black stain, they are likely dyed.

The Colorful Family of Sesame Seeds

While black and white are the most common, sesame seeds come in a range of colors, including tan, brown, gold, and gray. These different colors are the result of different cultivars of the Sesamum indicum plant. Just as there are many varieties of apples, there are many varieties of sesame, each with its unique characteristics, including seed coat color. The deeper the seed coat color, the higher the concentration of pigments like melanin and often, the more potent the nutritional content and flavor.

Comparison: Black vs. White Sesame Seeds


Feature	Black Sesame Seeds	White Sesame Seeds
Hull	Unhulled (outer coat intact)	Hulled (outer coat removed)
Color	Natural black or deep brown/gray	Light cream or white (inner kernel)
Flavor	Stronger, more intense, nutty, slightly bitter	Milder, sweeter, and nutty
Texture	Crunchy due to the hull	Softer, less crunchy
Nutritional Profile	Higher in calcium, iron, fiber, and antioxidants (lignans) due to the hull	Lower in some nutrients due to hull removal
Common Uses	Asian desserts, garnish on savory dishes, pastes	Tahini, baked goods, burger buns, general seasoning

Conclusion

In conclusion, the dark color of black sesame seeds is a completely natural phenomenon. It is a defining characteristic of specific varieties of the Sesamum indicum plant and is attributed to the presence of melanin in their intact outer hull. The retention of this hull not only gives the seeds their signature color but also provides a more complex flavor and a higher concentration of beneficial nutrients, distinguishing them from their milder, hulled white counterparts. For consumers, a simple test can help ensure the authenticity of the product, confirming that the striking black color is a gift from nature, not a chemical dye.

For further reading on the scientific analysis of black sesame pigments, see the Frontiers article "The Dark Pigment in the Sesame (Sesamum indicum L.) Seed Coat".

Frequently Asked Questions

No, black and white sesame seeds come from the same plant species, Sesamum indicum. The difference in color is due to the cultivar (plant variety) and whether the outer hull is removed during processing.

To check for dye, place a few seeds in a glass of cold water. Real black sesame seeds will not bleed color immediately, while dyed seeds will quickly stain the water dark. You can also cut a seed in half to see if the inside kernel is white.

After soaking for an extended period, real black sesame seeds may release a faint, reddish-brownish pigment. This is a natural, gradual process of the pigment leaching out and is not a sign of artificial dye, unlike the immediate, dark color bleed from dyed seeds.

Black sesame seeds are generally considered to be slightly more nutrient-dense than white ones. This is because black sesame seeds retain their hull, which contains a higher concentration of antioxidants, calcium, and iron.

The black color is primarily contained within the outer seed coat or hull. The inner part of the seed, or endosperm, is white, which you can see if you cut the seed in half.

The more robust, nutty, and slightly bitter flavor of black sesame seeds comes from the presence of their intact outer hull. White sesame seeds, having been hulled, have a milder, sweeter taste.

Yes, they can often be substituted, but with some considerations. Black sesame seeds have a stronger flavor and crunchier texture, which can affect the final taste and appearance of a dish. The dramatic color and richer flavor may be more suited to certain recipes than others.