Black Sesame Seeds: What They Are and What's Actually in Them
Black sesame seeds are among the most commonly mis-shelved ingredients in a British kitchen cupboard. At a glance they look like several other small dark seeds, and the one they are most often mistaken for — black seed, sold as kalonji or nigella — is not a sesame at all but a completely unrelated plant. The confusion is not harmless. It sends people to the wrong jar, the wrong body of research and occasionally the wrong purchase. This article does two things. It settles what black sesame actually is, botanically and physically, so you can tell it apart in the palm of your hand. And it sets out what is genuinely in the seed, using published composition data rather than the folklore that dominates the topic.
If you arrived here looking for the black seed described in the hadith literature, that is a different plant — Nigella sativa — and you can read about our own cold-pressed Ethiopian black seed oil instead.
The Short Answer
- Black sesame is Sesamum indicum, in the family Pedaliaceae. Black seed, kalonji and nigella all refer to Nigella sativa, in the family Ranunculaceae. Kew's Plants of the World Online lists them in different families and different orders — they are not close relatives in any sense.
- You can separate them by eye. Sesame seeds are flat, smooth-sided ovals with a faint sheen. Nigella seeds are angular, faceted and matte, with no gloss at all.
- The headline mineral figures for sesame belong to the hull, not the colour. Whole unhulled sesame carries roughly 975 mg of calcium per 100 g; hulled kernels carry about 60 mg — a loss of around 94% (USDA FoodData Central entries 170150 and 169412).
- Content is not absorption. Sesame hulls are also where the oxalate and phytate sit, and both reduce how much of that calcium you actually take up.
- Whole sesame seeds have a tough coat. Grinding them, or chewing them properly, is what makes the inside available at all.
- No food has been shown to reverse grey hair, black sesame included. The pigment claims that dominate this topic are traditional, not demonstrated.
- Sesame is one of the 14 allergens that must be declared on food sold in the UK, and sesame allergy can be serious.
Black Sesame Is Sesamum indicum — Not Black Seed, Not Kalonji
Sesame is Sesamum indicum L., published by Linnaeus in Species Plantarum in 1753 and accepted under that name by Kew's Plants of the World Online and the World Checklist of Vascular Plants. It sits in the family Pedaliaceae, in the order Lamiales, and is native to the Indian subcontinent. If you have seen the name Sesamum orientale on an older paper or a seed packet, that is the same plant: Kew treats it as a heterotypic synonym.
Black seed is Nigella sativa L., in the family Ranunculaceae — the buttercups. Kew's own common name for it is, unhelpfully for everyone, "black cumin seed". A third seed, Elwendia persica (long known as Bunium persicum), is also sold in English as black cumin and is a member of the carrot family. Three plants, three families, one crowded English vocabulary.
| Sold as | Species | Family | Seed shape | Smell and taste |
|---|---|---|---|---|
| Black sesame, kuro goma, ellu | Sesamum indicum | Pedaliaceae | Flat oval, smooth, faintly glossy | Nutty, sweet, mild; stronger when toasted |
| Black seed, kalonji, nigella, black onion seed | Nigella sativa | Ranunculaceae | Angular, faceted, matte, no sheen | Immediately pungent, peppery, onion-like |
| Black cumin, kala zeera, shahi jeera | Elwendia persica | Apiaceae | Slender, curved, ridged like cumin | Smoky, earthy, cumin-adjacent |
The English tangle around Nigella sativa is a subject in its own right — we have set out the four seeds sold in English as "black cumin" in our guide to what jeera kala actually refers to, and the South Asian and Tamil naming in our piece on karunjeeragam in English. This is a distinction we have had to draw repeatedly across our own library, which is the honest reason this article opens with it.
How to Tell Black Sesame from Nigella in the Palm of Your Hand
Tip a few seeds into your palm and look at the edges. Black sesame seeds are flattened ovals with smooth, unbroken sides and a rounded point at one end; under decent light they carry a faint sheen from the oil in the coat. Nigella seeds are three-dimensional and angular, with flat faces meeting at hard edges, and they are completely matte.
Then crush one. Sesame smells of almost nothing until it is toasted, at which point it turns nutty and sweet. Nigella announces itself instantly — sharp, peppery, faintly like onion skin, which is exactly why it picked up the name "black onion seed" and, with it, another layer of confusion we have untangled separately in our article on the three oils sold as onion seed oil.
Size helps too, though less reliably. Both seeds are small, but sesame runs slightly longer and noticeably flatter. If a seed rolls, it is probably not sesame.
What Is Actually in Black Sesame Seeds
Sesame is about half fat by weight and unusually mineral-dense for a seed. The most useful published reference is USDA FoodData Central, which holds a Standard Reference entry for whole dried sesame seeds (170150) and a separate entry for hulled, decorticated kernels (169412). One honest caveat first: those entries are for sesame in general, not for black-seeded cultivars specifically. The difference the data captures is the hull, not the colour.
| Per 100 g | Whole, unhulled (FDC 170150) | Hulled kernels (FDC 169412) |
|---|---|---|
| Energy | 573 kcal | ~630 kcal |
| Protein | 17.7 g | ~20.5 g |
| Fat | 49.7 g | ~61 g |
| Fibre | 11.8 g | 11.6 g |
| Calcium | 975 mg | 60 mg |
| Iron | 14.6 mg | 6.4 mg |
| Magnesium | 351 mg | 345 mg |
| Copper | 4.08 mg | 1.4 mg |
Read the calcium row twice. Hulling removes roughly 94% of it, and more than half the iron, while magnesium barely moves. That is the single most useful fact on this page, and it has nothing to do with the seed being black. Black sesame is usually sold unhulled, which is why it tends to carry the higher figures — but so does unhulled white sesame.
Sesame also carries two lignans, sesamin and sesamolin, which are essentially unique to the genus and are the compounds behind most of the antioxidant research on the seed and its unrefined oil. Their content varies several-fold between cultivars, so it is a varietal trait rather than a colour one.
Black or White? What the Colour Changes, and What It Doesn't
The colour sits in the seed coat, and it comes with the pigments and phenolic compounds that live there. In practice black sesame is nuttier, faintly more bitter and considerably more assertive than pale hulled sesame — which is why it is used where it is meant to be tasted rather than merely scattered.
What the colour does not do is transform the seed nutritionally. Almost every comparison that circulates online is really comparing unhulled seed with hulled seed and crediting the difference to pigment. If you buy unhulled white sesame you get most of the same mineral profile.
Hulled black sesame is the case worth being careful about, because the label and the seed turn out to be two different things. The colour is a melanin-type polymer in the seed coat — isolated and characterised by Dossou and colleagues in Frontiers in Nutrition in 2022 — and the kernel underneath is ivory whatever colour the coat was. A genuinely decorticated black sesame seed is therefore not black. Packs and listings that say "hulled black sesame" nonetheless do exist: we found them on a major spice brand's own online store and at a US bulk seed seller, and in both cases the same manufacturer's catalogue entry for the same pack describes plain whole black sesame and says nothing about hulling, which suggests the word is carried over from the general sesame range rather than describing the seed. The rule that survives all of it is simple: if the seed in the bag is black, the coat is still on it, and the minerals are still with it. Our companion guide to what to check before you buy black sesame seeds works through the labelling in detail.
The practical version: buy on hulled or unhulled first, and on colour second, for taste.
The Grey Hair Question, Answered Honestly
Black sesame's best-known reputation, drawn from Chinese and Ayurvedic tradition, is as a food for hair colour. It is worth being direct: no food has been shown to reverse grey hair, and black sesame is not an exception.
The mechanism people reach for is real as far as it goes. Melanin is made by tyrosinase, a copper-dependent enzyme, and iron and copper are both required for normal pigment production; deficiency in either is associated with premature greying. Sesame is a genuinely good source of both. But "this food supplies a nutrient your pigment cells need" is a very different statement from "this food restores pigment to hair that has already lost it", and the second does not follow from the first.
Greying is driven largely by the exhaustion of the pigment-producing cells in the follicle, and by genetics and age. Eating well supports normal function; it does not reverse the clock. Anyone selling black sesame on a promise of reversing grey hair is selling you tradition dressed as a result.
Whole, Ground, Toasted or Pressed: Getting Anything Out of Them
Sesame has a tough seed coat, and a whole seed swallowed whole is largely a whole seed still. Grinding is the single change that makes the most difference — it is also why tahini and Japanese goma pastes exist. Toasting changes flavour rather than composition, and it does so quickly: black sesame burns before it looks burnt.
| Form | What changes | Best for | Watch out for |
|---|---|---|---|
| Whole, raw | Nothing; the coat stays intact | Coatings, breads, garnish, texture | Much of the seed passes through undigested |
| Whole, dry-toasted | Flavour deepens; aroma develops | Furikake, dressings, finishing | Goes from toasted to bitter in seconds |
| Ground or milled to paste | Coat is broken; contents become available | Black tahini, dressings, desserts | Oxidises faster once ground — make it in small batches |
| Cold-pressed black sesame oil | Fat and lignans are carried over; minerals are not | Finishing oil, or a cosmetic carrier oil | Not the same as supermarket toasted sesame oil, which is pressed from roasted hulled seed |
Black sesame oil is a real and separate product, cold-pressed from unhulled black seed and sold both as a finishing oil and as a carrier oil for the skin and scalp. Some sellers attach hair-pigment claims to it. Those claims are not supported, and the same caution in the section above applies.
Buying and Storing Black Sesame Seeds
In the UK, black sesame is easiest to find in East Asian and South Asian grocers, and in the world-foods aisle of larger supermarkets, usually in 100 g to 500 g packs. Look for "unhulled" or "whole" on the label if minerals are the point, and check whether the pack says raw or roasted — the two behave differently in a pan.
Storage matters more than people expect for a seed that is half fat. Keep the pack sealed, cool and out of the light, and buy quantities you will finish within a few months rather than a catering bag you will not. Ground sesame and sesame pastes should go in the fridge once opened.
One safety note that is not optional: sesame is one of the 14 allergens UK law requires to be declared on food, and sesame allergy can be severe. If you are cooking for other people, treat it the way you would treat nuts.
Three Objections Worth Taking Seriously
"Isn't the name thing just pedantry?"
It would be, if the two seeds were interchangeable. They are not. They belong to different plant families, taste nothing alike, are used in different dishes and have entirely separate research literatures. Somebody who buys black sesame after reading about Nigella sativa has bought a perfectly good ingredient and not the thing they were looking for.
"That calcium figure looks too good to be true."
It is a content figure, not an absorption figure, and that distinction matters here more than usual. The hull that carries the calcium also carries oxalate and phytate, both of which bind minerals and reduce uptake. Sesame is a useful contributor to a varied diet; it is not a shortcut around dairy or leafy greens.
"If the hull is where the good stuff is, why sell hulled sesame at all?"
Because the hull is also where the bitterness is. Hulled seed makes smoother, sweeter tahini, sits better in delicate baking and keeps slightly longer. That is a legitimate trade-off, openly made — the problem is only when a hulled product is sold on unhulled numbers.
Why Sidr & Stone
We do not sell sesame. We sell one thing — a cold-pressed oil from the other black seed, the one this article spends its first half separating from this one. The reason we wrote a sesame article at all is that the naming problem is ours as much as anyone's, and the honest fix is a clear page rather than a hopeful assumption. What we can offer on our own product is the thing this category almost never provides: a measured number.
- Independently verified 2.67% thymoquinone, tested per batch by Analytice, an ISO-accredited French laboratory, with a Certificate of Analysis you can actually look at
- Organically grown Ethiopian highland Nigella sativa — selected after a 36-supplier evaluation
- Cold-pressed below 40°C to protect the heat-sensitive thymoquinone
- 100% pure — a single ingredient, nothing added
- Unrefined, which preserves the oil's natural integrity
- Bottled in matte black UV-protective glass
- Halal certified
- 10% of profits to charity
- Fulfilment in the UK, EU, and US
We will not tell you Sidr & Stone is the strongest or the best — that would be the very kind of claim this article warns against. What we will say is that our thymoquinone figure is 2.67%, independently verified per batch, and the evidence is there to see. If you want the full walkthrough of how to judge any bottle on the shelf, our guide to choosing a quality black seed oil sets out the checks in order.
Frequently Asked Questions
Are black sesame seeds the same as black seed or kalonji?
No. Black sesame is Sesamum indicum, in the family Pedaliaceae. Black seed, kalonji and nigella are all names for Nigella sativa, in the family Ranunculaceae. They are unrelated plants that happen to produce small dark seeds.
What is the difference between black and white sesame seeds?
Mostly the seed coat. Black sesame is normally sold unhulled, so it keeps the coat and the minerals in it; white sesame is usually hulled, which strips most of the calcium and much of the iron. Black also tastes nuttier and slightly more bitter. You will occasionally see a pack labelled "hulled black sesame": the ones we checked held ordinary whole black seed, because hulling would take the colour away with the coat. Our guide to what to check before you buy black sesame seeds sets that out in full.
Do black sesame seeds reverse grey hair?
There is no evidence that they do. Copper and iron are needed for normal pigment production and sesame supplies both, but supplying a nutrient is not the same as restoring colour to hair that has already gone grey. Treat the claim as tradition, not a result.
Do you need to grind black sesame seeds?
If you want more than texture from them, yes. The coat is tough enough that whole seeds largely pass through undigested. Grinding them, blending them into a paste or chewing them thoroughly all solve the same problem.
Are black sesame seeds a good source of calcium?
Whole unhulled sesame is unusually calcium-dense on paper — around 975 mg per 100 g in USDA FoodData Central entry 170150. Absorption is another matter, because the same hull carries oxalate and phytate. It is a useful contributor to a varied diet rather than a substitute for other sources. For any specific dietary concern, speak to a GP or a registered dietitian.
Is black sesame oil the same as toasted sesame oil?
No. Black sesame oil is cold-pressed from unhulled black seed. The toasted sesame oil in most supermarkets is pressed from roasted, usually hulled, white seed — a difference of roasting and hull, not of seed colour.
Where can I buy black sesame seeds in the UK?
East Asian and South Asian grocers carry them reliably, and larger supermarkets often stock them in the world-foods aisle. Check the pack for "unhulled" or "whole", and for whether the seed is raw or already roasted.
Is black seed oil a medicine?
No. Black seed oil is a food supplement, not a medicine. It has a long traditional history and an interesting body of research around thymoquinone, and can be a worthwhile part of a healthy routine — but it does not cure diseases and is not a substitute for medical care. Be cautious of any black seed oil marketed with specific disease-cure claims.
Final Thoughts
Black sesame is a good ingredient with a bad information problem. Almost everything written about it either borrows the mineral figures of unhulled seed to sell a colour, or borrows the reputation of an entirely different plant to sell a promise. Strip both away and what is left is genuinely worth having: a nutty, mineral-dense, half-fat seed that rewards grinding, toasting carefully and buying unhulled.
The naming problem is the part worth carrying away. Sesamum indicum and Nigella sativa are not relatives, not substitutes and not interchangeable in a recipe or in a research paper. Once you can tell them apart by shape and smell, the rest of the shelf gets much easier to read.
And if it was the other black seed you were looking for, our cold-pressed Ethiopian black seed oil — independently verified at 2.67% thymoquinone — is available now, with fulfilment in the UK, EU, and US.
Shop Sidr & Stone Cold-Pressed Ethiopian Black Seed Oil — Verified 2.67% Thymoquinone →
Disclaimer: This article describes botanical, culinary and published composition information about black sesame seeds at the time of writing; composition data, product specifications and retail availability may change, and readers should check current sources. Black seed oil is a food supplement, not a medicine, and is not a substitute for medical treatment of any condition. For any health concern, including food allergy, consult a qualified medical professional.