γ-Terpinene
Also written gamma-terpinene, g-terpinene, terpinene
Quick answer
A mild, faintly citrus terpene that matters less for what it smells of than for what it turns into: p-cymene, which is why an ageing spice grows harsh rather than merely faint.
What it does
On its own γ-terpinene is unremarkable — lightly citrus, slightly woody, and rarely the note anyone identifies in a spice. It accompanies thymol and carvacrol in thyme, oregano and savory, and cuminaldehyde in cumin, where it contributes freshness at the top of the smell without shaping it.
How it behaves when cooked
Four properties of the molecule, and what they mean at the stove.
- Volatility
- high
- Fat solubility
- high
- Water solubility
- low
- Heat stability
- low
Its importance is as a precursor rather than as a smell. γ-Terpinene oxidises readily to p-cymene, and that single reaction explains the most confusing thing about old spices: a stale cumin or a stale oregano does not smell like a weaker fresh one, it smells sharper and slightly solvent-like. The compound that was contributing freshness has become the compound that contributes a dry, turpentine-adjacent harshness, so the profile has changed rather than faded. That is why toasting will not rescue a genuinely old spice, and why the storage advice in this dataset says a spice smelling harsh is further gone than one smelling faint.
Spices that carry it
Recorded on the compound rather than on each spice, so the two cannot disagree.
- AjwainContributing component
- Black cardamomContributing component
- Black cuminContributing component
- Coriander seedContributing component
- CuminContributing component
- OreganoContributing component
- SavoryContributing component
- ThymeContributing component
- Za'atar herbContributing component
Not to be confused with
Compounds a reader is likely to take for this one, and why they differ.
p-Cymene
What it becomes. The pair is the clearest chemical account of ageing in this catalogue: one oxidises into the other, and the spice goes from fresh to harsh rather than from strong to weak.
Questions this page answers
- what is gamma-terpinene
- what does gamma-terpinene do
- which spices contain gamma-terpinene