Home › Glossary › Phenylacetaldehyde

Phenylacetaldehyde

Q: Is Phenylacetaldehyde natural or synthetic?

. Extraction: Produced synthetically by Wacker oxidation of styrene, or by decarboxylation of phenylpyruvic acid. Found naturally in many flowers and foods but not commercially isolated from natural sources. The molecule's instability (tendency to oxidize and polymerize) means that freshness of the synthetic batch is important..

FLOWERS / floral · green · rosy

Phenylacetaldehyde

Category	FLOWERS
Subcategory	floral · green · rosy
Origin
Volatility	Top Note
Botanical	N/A — synthetic (also found naturally in Hyacinthus orientalis)
Appearance	colorless to pale yellow clear oily liquid
Odor Strength	High
Producing Countries	China, Europe, United States
Pyramid	Top

Green, hyacinth-like with a piercing, slightly narcotic floralcy. Phenylacetaldehyde smells like crushed hyacinth flowers in a greenhouse — intense, green-sweet, with a honeyed, almost alarming brightness.

Scent
The Full Story
Fun Fact
Extraction & Chemistry
In Perfumery

Scent

Intensely green-floral, hyacinth-like. Piercing, sweet, with a narcotic, almost alarming brightness. Honey-like undertone. More intense than florhydral, more green than hydroxycitronellal, less clean than linalool. Powerful and penetrating — must be used with restraint. On blotter, the aldehyde character evolves toward a gentler, honey-green residue.

Evolution over time

Immediately

Piercing green-floral burst. Hyacinth-like, narcotic, intense.

After a few hours

Honeyed-green heart. Intensity moderates. Floral sweetness emerges.

After a few days

Honey-green residue. Moderate tenacity despite high volatility.

The Full Story

CAS 122-78-1. An aromatic aldehyde with a powerful, green-floral, hyacinth-like scent. Phenylacetaldehyde occurs naturally in many flowers (hyacinth, narcissus, rose, linden) and foods (chocolate, wine, cheese). It is a important molecules for constructing hyacinth and narcissus accords.

The scent is intense — green, sweet, and piercingly floral. It has a narcotic quality similar to of standing in a greenhouse full of hyacinths. At high concentrations, it can be almost overwhelming; at proper dosage, it provides a luminous, green-floral brightness. The molecule is reactive and unstable — it oxidizes easily and can polymerize — which makes it challenging to work with in formulation.

Phenylacetaldehyde is also the primary volatile responsible for the scent of buckwheat honey — its presence in honey at high levels gives buckwheat honey its particular, almost unpleasant intensity.

This note in Première Peau. Nuit Elastique · Rose Monotone. Sample all seven extraits in the Discovery Set.

—

Did You Know?

Did you know?

Phenylacetaldehyde is the molecule that makes buckwheat honey smell so different from clover or acacia honey. Its concentration in buckwheat honey can be 100x higher than in lighter honeys — which is why buckwheat honey has a pungent, almost overwhelming character that divides opinion sharply.

Extraction & Chemistry

Extraction method: Produced synthetically by Wacker oxidation of styrene, or by decarboxylation of phenylpyruvic acid. Found naturally in many flowers and foods but not commercially isolated from natural sources. The molecule's instability (tendency to oxidize and polymerize) means that freshness of the synthetic batch is important.

Molecular Formula	C8H8O
CAS Number	122-78-1
Botanical Name	N/A — synthetic (also found naturally in Hyacinthus orientalis)
IFRA Status	No known restrictions
Synonyms	2-PHENYLACETALDEHYDE · PHENYLACETALDEHYDE
Physical Properties
Odor Strength	High
Lasting Power	400 hour(s) at 100.00 %
Appearance	colorless to pale yellow clear oily liquid
Boiling Point	193.00 to 195.00 °C. @ 760.00 mm Hg
Flash Point	189.00 °F. TCC ( 87.00 °C. )
Specific Gravity	1.02500 to 1.03500 @ 25.00 °C.
Refractive Index	1.52500 to 1.53200 @ 20.00 °C.

In Perfumery

Top-to-heart modifier in hyacinth, narcissus, and green-floral compositions. Phenylacetaldehyde provides the intense green-floral character that defines hyacinth accords (alongside cinnamyl alcohol and florhydral). In narcissus reconstructions, it provides the narcotic, green-honey quality. Used at very low concentrations — typically 0.05-0.5% — due to its extreme potency. The molecule's instability requires careful formulation; it is often used as a Schiff base (e.g., with methyl anthranilate) to improve stability.