Two distinct oils reach the market under the word peppermint, and the difference is not a technicality. Mentha piperita oil (CAS 8006-90-4) and Mentha arvensis oil (CAS 68917-18-0) come from different plants, carry different compositions and command different prices. Specifying the wrong one produces a product that works but does not taste the way the brief intended.

Mentha piperita: true peppermint

Piperita is what most flavourists mean by peppermint. It carries a rounded, sweet, slightly fruity top note alongside its cooling character, and a naturally balanced menthol-to-menthone ratio. It is the more expensive of the two and the one specified where the mint note is the hero of the product rather than a background cooling effect.

Mentha arvensis: cornmint

Arvensis, or cornmint, is naturally far higher in menthol. In practice most of that menthol is crystallised out, which is precisely how menthol crystals and dementholised mint oil are produced. Arvensis-derived peppermint oil is sharper and more directly cooling, with less of the sweet complexity of piperita, and it is materially cheaper.

Where each belongs

Premium confectionery and fine flavour: piperita, where the note is the selling point.
Toothpaste and mouthwash: often arvensis-derived, where cooling and cost dominate and other flavour materials carry the profile.
Pharmaceutical and digestive preparations: depends on the monograph; check what the pharmacopoeia actually specifies before assuming.
Chewing gum: frequently a blend, tuned to hold flavour through the chew.

The substitution question

Swapping arvensis for piperita to save cost is common and sometimes entirely appropriate. It becomes a problem when it is done silently in a product whose identity rests on the mint character, or where a specification names the botanical source. The safer approach is to reformulate deliberately, adjusting the rest of the flavour system to compensate, rather than treating the two as interchangeable line items.

What to check on the COA

Look at menthol and menthone content, and confirm the botanical source is stated rather than implied. A supplier that distils and processes both, as Gem Aromatics does across its mint range, can quote either against the same specification format, which makes the comparison meaningful. Related materials worth considering include spearmint oil where a softer, carvone-led mint is wanted.