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Mustard Seed

Q: Is Mustard Seed natural or synthetic?

. Extraction: Mustard essential oil (allyl isothiocyanate) is obtained by steam distillation of crushed Brassica nigra or B. juncea seeds after enzymatic activation. The oil is extremely pungent and toxic at concentration — it is a powerful lachrymator. Handled only by specialists. White mustard (Sinapis alba) produces a milder oil with different chemistry..

SPICES / spicy · warm · fresh

Mustard Seed

Category	SPICES
Subcategory	spicy · warm · fresh
Origin
Volatility	Top Note
Botanical	Brassica nigra
Appearance	Pale yellow to colorless liquid with extremely pungent, lachrymatory odor (essential oil)
Odor Strength	High
Producing Countries	Asia, Europe
Pyramid	Heart

Pungent, hot, acrid. Sinapis alba or Brassica — the sharp bite of isothiocyanates released when seeds are crushed and moistened, a chemical defense weaponized as spice.

Scent
The Full Story
Fun Fact
Extraction & Chemistry
In Perfumery

Scent

Pungent, sharp, nasal-stinging. The isothiocyanate is more nose-burning than cinnamon, more acrid than pepper, with a specific sinus-clearing quality shared with wasabi and horseradish. At extreme dilution: a sharp, slightly sulfurous warmth. The whole seed (unbroken) is nearly odorless — the pungency is generated on demand.

Evolution over time

Immediately

Sharp pungent burst, nasal-stinging

After a few hours

Warm, slightly sulfurous, subdued

After a few days

Faint warm residue, pungency gone

The Full Story

Mustard seed (Sinapis alba, Brassica nigra, Brassica juncea) has a complex olfactory behavior: whole seeds are nearly odorless, but crushing and moistening them triggers an enzymatic reaction between myrosinase and sinigrin (a glucosinolate), producing allyl isothiocyanate — the pungent molecule responsible for mustard's bite.

This enzymatic defense mechanism is shared across the Brassicaceae family (wasabi, horseradish, radish). The isothiocyanate produced is a lachrymator — it triggers pain receptors in the nose and eyes. The pungency is not heat (like chili capsaicin) but a sharp, nasal-stinging quality.

In perfumery, mustard seed is a rare, extreme spice note. The isothiocyanate pungency is too aggressive for most compositions, but at extreme dilution it can add a sharp, horseradish-like bite to spicy and dark compositions.

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Related: Allspice · Anethole · Anise · Asafoetida · Baking Spices · Bay Leaf · Biryani · Caraway

Did You Know?

Did you know?

Allyl isothiocyanate, mustard's pungent molecule, activates the exact same receptor (TRPA1) as tear gas, wasabi, and the Carolina Reaper. The plant produces it as a chemical weapon against herbivores — the myrosinase-sinigrin 'bomb' only detonates when the seed is damaged, a system called a 'chemical binary weapon.'

Extraction & Chemistry

Extraction method: Mustard essential oil (allyl isothiocyanate) is obtained by steam distillation of crushed Brassica nigra or B. juncea seeds after enzymatic activation. The oil is extremely pungent and toxic at concentration — it is a powerful lachrymator. Handled only by specialists. White mustard (Sinapis alba) produces a milder oil with different chemistry.

Molecular Formula	C₄H₅NS (Allyl isothiocyanate, key pungent compound)
CAS Number	8007-40-7
Botanical Name	Brassica nigra
IFRA Status	No known restrictions
Synonyms	BLACK MUSTARD · BROWN MUSTARD · WHITE MUSTARD
Physical Properties
Odor Strength	High
Appearance	Pale yellow to colorless liquid with extremely pungent, lachrymatory odor (essential oil)
Flash Point	190.00 °F. TCC ( 87.78 °C. )
Specific Gravity	0.91300 to 0.92300 @ 25.00 °C.
Refractive Index	1.46200 to 1.48200 @ 20.00 °C.

In Perfumery

Mustard seed is an extreme spice note rarely used in perfumery. The isothiocyanate is too pungent and irritating for most applications. At extreme dilution, it can provide a sharp, horseradish-like accent in dark-spicy and provocative compositions. Built from allyl isothiocyanate (at extreme dilution) or approximated using sharp-pungent synthetics.