Peppermint vs spearmint: why do they smell different?
Menthol, menthone and carvone give familiar mint oils different characters.
In this article
Peppermint and spearmint oils contain different mixtures of aromatic compounds. In the samples studied, menthol and menthone stood out in peppermint, while carvone dominated spearmint.
“Mint” is a starting point
If two things are both described as minty, it is tempting to expect the same smell. Essential oils are mixtures, though, and the balance of their components matters.
Different mixtures, different characters
A 2019 analysis compared peppermint, native spearmint and Scotch spearmint oils. The peppermint sample contained substantial menthol and menthone; carvone was the predominant component in both spearmint samples. The authors also discussed variation between oils from different growing conditions. [1]
Those results describe the oils tested. They are not percentages for a viff formula, nor a guarantee that every bottle of an oil will have exactly the same composition.
Quantity is not the only part of smell
Another study used chemical analysis alongside smell-based testing to identify potent odour contributors in three spearmint oils. Carvone was the most potent odorant in all three. [2]
That helps explain why looking only at an ingredient name, or at a single percentage, can miss what gives a mixture its recognisable character.
Why a blend can use both
For a scent maker, peppermint and spearmint are different materials to work with. Combining them can be a choice about the character of a scent. It does not mean one oil is universally better than the other.