In short
Whisky lactone, or oak lactone, is the lactone that oak barrels give to aged whisky, wine and cognac. It has a warm coconut and toasted-oak odour.
What Whisky Lactone smells like
Whisky lactone, or oak lactone, was identified in 1970 in spirits aged in oak, where both its cis and trans isomers occur. A review describes isomer mixtures as coconut-like, the cis isomer as woody and earthy and the trans as celery-like; the cis isomer is the more important to the senses. A supplier gives warm, sweet and coumarin-like; at 0.5 ppm its taste is woody, coumarinic, coconut, lactonic, creamy and nutty with a toasted nuance. American oak yields more of it than European oak.
- Leading note
- Coconut-wood
- Supporting facets
- Coumarin, toasted
- Faint facets
- Nutty, celery
- Character
- Warm, woody, sweet, dry
What makes Whisky Lactone distinctive
Coconut with a woody, earthy edge rather than a creamy one — the note oak barrels give to whisky and wine.
Where the descriptions disagree: Sources disagree on the isomers' odours: one gives the cis isomer as woody and earthy and the trans as celery-like, while supplier descriptions of the mixture are warm, sweet and coumarin-like.
How Whisky Lactone is used
Used in boozy, woody and gourmand accords, in whisky, cognac and rum effects, and in tobacco blends.
Typical role: modifier (used in small amounts to change the character of a blend).
How Whisky Lactone differs from similar materials
- gamma-Nonalactone (Aldehyde C-18)
- gamma-Nonalactone is coconut without wood — creamy and buttery; whisky lactone carries its coconut inside a woody, toasted, coumarinic character.
- Methyl Laitone
- Methyl Laitone is a creamier coconut-milk lactone with a coumarin side; whisky lactone pairs its coconut with oak wood.
- Oakwood CO2 Extract
- Oakwood CO2 is the whole toasted wood: oak, vanilla, smoke and dried fruit, of which whisky lactone is one part.
Each difference compares the published descriptions of the two materials. Smell varies with grade, supplier and dilution; compare them side by side on blotters before substituting one for another.
Identity and classification
- Type
- Aroma chemical
- Origin
- Occurs in nature
- Odour family
- Woody / Gourmand
- Note position
- Heart to base note
- Physical form at room temperature
- Liquid
- Also known as
- Oak lactone, beta-Methyl-gamma-octalactone, 5-Butyl-4-methyldihydro-2(3H)-furanone
- CAS number
- 39212-23-2
- Molecular formula
- C9H16O2
- Molecular weight
- 156.22 g/mol
- IUPAC name
- 5-butyl-4-methyloxolan-2-one
The CAS number, formula and molecular weight are taken from PubChem compound 62900, whose own record lists this CAS number; checked 19 October 2026.
Safety and compliance
Hazard classification of the neat substance, as PubChem summarises it, read 26 October 2026. Companies notifying the ECHA C&L Inventory classify it (278 reports): H315 causes skin irritation (14% of reports); H319 causes serious eye irritation (14% of reports); H335 may cause respiratory irritation (13.7% of reports). 239 of the reports find it does not meet the hazard criteria. Unless it is harmonised, this is the notifiers' own classification, not a binding one.
This page is general information, not a safety assessment or a specification. Confirm identity, composition, IFRA status and allergen content from your supplier's documents for the lot you hold.
Materials it works with
-
Coumarin
Aroma chemical · Powdery / Fougère — hay, sweet, almond, tobacco
-
Vanillin
Aroma chemical · Gourmand / Amber — vanilla, sweet, creamy
-
Guaiac Wood Oil
Essential oil · Woody / Resinous — smoky, woody, rosy, sweet
-
Tonka Bean Absolute
Absolute · Gourmand / Powdery — coumarinic, hay, almond, sweet
Whisky Lactone is also suggested as a partner on the pages for Cognac Oil (Green), Oakwood CO2 Extract, Rum Ether and Tobacco Absolute.
Used in formulas and accords
Used in 7 published formulas
Whisky Lactone is an ingredient in 4 perfume formulas and 3 accords in the Formula & Accord Library.
Community formulas
RUŌOD House Originals
Original compositions by RUŌOD House.
Further reading
Questions about Whisky Lactone
Is Whisky Lactone natural or synthetic?
The molecule occurs in nature. Commercial Whisky Lactone may be made by synthesis or obtained from natural sources, so check the supplier's specification if the distinction matters to you.
What is the CAS number of Whisky Lactone?
39212-23-2. It was checked against PubChem on 19 October 2026.
Which published formulas use Whisky Lactone?
Whisky Lactone is used in 7 published formulas in the RUŌOD Lab Formula & Accord Library, including Apple Cellar, Coconut Accord and Cola Amber. Each is listed with a link under "Used in formulas and accords" on this page.
Sources
- PubChem — compound 62900, checked 19 October 2026.
- PubChem — GHS classification (the ECHA C&L Inventory notifications and any harmonised EU entry), read 26 October 2026.
- Frontiers in Microbiology (2023) — whisky lactone review — published literature.
- ChemicalBook — whisky lactone (CAS 39212-23-2) — odour database.
- Wine with Seth — oak lactones — published perfumery reference.
- Olfactory profile: the RUŌOD Lab team's synthesis of the published descriptions above, reviewed 24 October 2026. Evidence: more than one published description. Classification and the short description: revision 1. Descriptions of odour are judgement, not measurement.