In short
Milk Lactone is the trade name of a mixture of 5- and 6-decenoic acids. Despite its name it is an acid, with a clearly milky odour and a natural green quality.
What Milk Lactone smells like
Fraterworks describes Milk Lactone — so called although it is really an acid — as clearly milky with an unusual but rather natural green quality, completed by a hint of cheese and floralcy, and suggests it for a peach-skin effect in fruity bases and in gardenia bases. PubChem's substance records give the number as 5- and 6-decenoic acid (FEMA 3742). The Fragrance Foundry, selling ACS International's milk lactone (5(6)-decenoic acid, the same CAS number), uses it to recreate a milk or dairy note and finds that it smells like milk-bottle sweets.
- Leading note
- Milky
- Supporting facets
- Green
- Faint facets
- Cheesy, floral
- Character
- Creamy, natural
What makes Milk Lactone distinctive
Clearly milky with a natural green quality and a hint of cheese — named a lactone though it is an acid.
Where the descriptions disagree: PubChem's compound record for 72881-27-7 is trans-2-decenoic acid, while its substance records and suppliers give 5- and 6-decenoic acids; the substance identity is the one used here.
How Milk Lactone is used
Used for milky and creamy notes, to add a peach-skin effect to fruity bases, in gardenia bases and with other lactones.
Typical role: modifier (used in small amounts to change the character of a blend).
How Milk Lactone differs from similar materials
- Butyl Butyryllactate
- Butyl butyryllactate is the sour, buttery buttermilk; milk lactone is sweeter milk with a green, peach-skin quality.
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.
Formulation considerations
Not the same as products sold as "Milk Lactone Super" or "Milk Lactone (Mixture)", which Fraterworks describes as bases built around delta-dodecalactone. Natural occurrence is recorded for decenoic acids generally, not checked for this mixture.
Identity and classification
- Type
- Aroma chemical
- Origin
- Occurs in nature
- Odour family
- Gourmand / Green
- Note position
- Heart to base note
- Physical form at room temperature
- Liquid
- Also known as
- 5- and 6-Decenoic acid, Decenoic acid (FEMA 3742)
- CAS number
- 72881-27-7
The CAS number was checked on 25 October 2026 against a PubChem substance record that gives it for this material. Milk Lactone is sold as a mixture of 5- and 6-decenoic acids (an acid, despite its name); PubChem's compound record for the same number shows trans-2-decenoic acid, a different isomer, so no single structure is shown. So no single formula, molecular weight or structure drawing is given.
Safety and compliance
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
-
delta-Dodecalactone
Aroma chemical · Gourmand / Fruity — creamy, buttery, coconut, peach
-
gamma-Decalactone
Aroma chemical · Fruity / Gourmand — peach, fruity, creamy
-
Stemone
Aroma chemical · Green / Fruity — green, fig leaf, leafy, fruity
Milk Lactone is also suggested as a partner on the pages for Cremefleur.
Used in formulas and accords
Used in 20 published formulas
Milk Lactone is an ingredient in 9 perfume formulas and 11 accords in the Formula & Accord Library.
Community formulas
RUŌOD House Originals
Original compositions by RUŌOD House.
Further reading
Questions about Milk Lactone
Is Milk Lactone natural or synthetic?
The molecule occurs in nature. Commercial Milk 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 Milk Lactone?
72881-27-7, the registry number for the aroma chemical as a substance rather than a single molecule. It was checked against PubChem on 25 October 2026.
Which published formulas use Milk Lactone?
Milk Lactone is used in 20 published formulas in the RUŌOD Lab Formula & Accord Library, including Cappuccino Accord, Cardamom Crema and Chocolate Accord. Each is listed with a link under "Used in formulas and accords" on this page.
Sources
- PubChem — substance 126684705, checked 25 October 2026.
- Fraterworks — Milk Lactone — distributor's description.
- PubChem — Milk lactone, 72881-27-7 (substance) — odour database.
- The Fragrance Foundry — Milk lactone (ACS International) — distributor's description.
- Olfactory profile: the RUŌOD Lab team's synthesis of the published descriptions above, reviewed 26 October 2026. Evidence: more than one published description. Classification and the short description: revision 1. Descriptions of odour are judgement, not measurement.