In short
Castoreum absolute is a solvent extract of the dried castor sacs of the beaver. It is intensely leathery and animalic, with a sweet, fruity side in refined grades.
What Castoreum Absolute smells like
Fraterworks describes a castoreum absolute from Floral Concept (Canada, Castor canadensis) as intensely leathery, a black solid without the off-notes of most products, and Robertet's Castoreum Hyperessence as a particularly clean absolute that tones down the rough edges and enhances sweet raspberry facets. Britannica describes castoreum as the oily secretion of two pairs of sacs in the beaver, removed after trapping and dried. The Good Scents Company lists castoreum absolute as leathery, smoky, animal, phenolic, old wood, burnt and resinous.
- Leading note
- Leather
- Clear facets
- Animalic
- Supporting facets
- Sweet
- Faint facets
- Raspberry
- Character
- Dark, tenacious
What makes Castoreum Absolute distinctive
Intensely leathery and animalic, the refined grades bringing out sweet, raspberry-like facets.
Concentration and dilution
A solid at room temperature; Fraterworks sells it at 50% (in benzyl benzoate or triethyl citrate).
How Castoreum Absolute is used
Used in leather, chypre, fougère and amber accords as an animalic leather note and fixative.
Typical role: fixative (slow to evaporate; helps a blend last and holds lighter notes); modifier (used in small amounts to change the character of a blend).
How Castoreum Absolute differs from similar materials
- Civet Absolute
- Civet absolute is fecal and furry; castoreum is the leathery, smoky-phenolic animal note, with sweet raspberry facets in the refined grades.
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
An animal product: the castor sacs are taken from beavers (Castor canadensis), which are trapped, mainly for fur, and sold as a by-product. Demand for castoreum contributed to the near-extinction of North American beavers by 1900. A solid, usually sold diluted; synthetic reconstructions are widely available.
Identity and classification
- Type
- Absolute
- Origin
- Natural
- Odour family
- Animalic / Leather
- Note position
- Base note
- Physical form at room temperature
- Solid
- CAS number
- 8023-83-4
The CAS number was checked on 25 October 2026 against a PubChem substance record that gives it for this material. A natural material is a mixture, so it has no single formula; its composition varies with origin and processing.
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
-
Birch Tar Oil (Rectified)
Essential oil · Leather / Woody — smoky, leathery, tarry, phenolic
-
Labdanum Absolute
Absolute · Amber / Leather — amber, balsamic, leathery, animalic
-
Isobutyl Quinoline
Aroma chemical · Leather / Green — leathery, earthy, green, smoky
Used in formulas and accords
Used in 22 published formulas
Castoreum Absolute is an ingredient in 16 perfume formulas and 6 accords in the Formula & Accord Library.
Community formulas
RUŌOD House Originals
Original compositions by RUŌOD House.
Further reading
Questions about Castoreum Absolute
Is Castoreum Absolute natural or synthetic?
Castoreum Absolute is natural. It is a concentrated extract obtained from plant material with a solvent, then washed with ethanol to remove the waxes.
What is the CAS number of Castoreum Absolute?
8023-83-4, the registry number for the absolute as a substance rather than a single molecule. It was checked against PubChem on 25 October 2026.
Which published formulas use Castoreum Absolute?
Castoreum Absolute is used in 22 published formulas in the RUŌOD Lab Formula & Accord Library, including Amber Accord, Beeswax Throne and Bitter Bridle. Each is listed with a link under "Used in formulas and accords" on this page.
Sources
- PubChem — substance 135333337, checked 25 October 2026.
- Fraterworks — Castoreum Signature Absolute 50% — distributor's description.
- Fraterworks — Castoreum Hyperessence 50% TEC — distributor's description.
- Encyclopaedia Britannica — castoreum — published perfumery reference.
- The Good Scents Company — castoreum odour category — odour database.
- 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.