What Is a Citrus Accord, and What Is the Secret of Cologne?
The freshness that hits you when you open a bottle of lemon cologne does not come from a single fruit. Behind it is a balanced citrus accord: several citrus oils, a little flower, a little leaf.
The citrus (hesperidic) accord is one of the oldest structures in perfumery and the foundation of classic cologne. Why an accord? Because a single citrus oil is one-dimensional: lemon is sharp but thin, orange is sweet but flat, bergamot is elegant but incomplete on its own. Used together they give a bright, rounded and lively opening.
| Material | CAS No | Ratio | Role in the accord |
|---|---|---|---|
| Bergamot Oil (bergapten-free) | 8007-75-8 | 30% | Elegant, floral citrus body |
| Lemon Oil | 8008-56-8 | 20% | Sharp, bright opening |
| Sweet Ratioge Oil | 8008-57-9 | 12% | Juicy, sweet fullness |
| Petitgrain Oil | 8014-17-3 | 10% | Green, woody leaf tone |
| Linalool | 78-70-6 | 8% | Floral bridge |
| Linalyl Acetate | 115-95-7 | 8% | Sweetness that extends the bergamot |
| Hedione | 24851-98-7 | 5% | Transparent diffusion, extension |
| Neroli Base | — | 4% | Ratioge-blossom elegance |
| Rosemary Oil | 8000-25-7 | 3% | Aromatic, herbal liveliness |
Component by Component: The Role of Each Material
The accord is built in three layers: fruit, leaf and flower, and extenders.
Bergamot is the body of the accord. It is less sharp than other citrus, more floral and more complex; the linalool and linalyl acetate it contains give it this elegance. Lemon adds brightness and sharpness to the opening, orange a juicy sweetness. Together the three build the perception of "citrus" without tying it to a single fruit.
Petitgrain is obtained from the leaves and twigs of the bitter orange tree. It brings the green, slightly bitter and woody tone that the fruit oils cannot give; this is what moves the accord from fruit juice to perfume. Neroli is orange blossom; even a small dose gives the accord an elegant florality. Because natural neroli oil is very expensive, a ready-made base is mostly used.
Rosemary is the aromatic signature of classic cologne; with its herbal, slightly camphoraceous liveliness it balances the citrus.
Linalool, linalyl acetate and Hedione are the extenders. Citrus oils evaporate within minutes; these three molecules carry the character of bergamot and so prolong the sensation of freshness into the heart. Hedione also gives the accord a transparent, airy diffusion.
Building the Accord: Order, Layering and Storage
A citrus accord is the easiest accord to build and the hardest to preserve.
- Start with fresh oil
Citrus oils oxidise quickly. Do not use oil that has been open for a long time, has gone dull, or smells of turpentine.
- Build the fruit layer
Combine bergamot, lemon and orange. Try out the balance by changing the ratios: more lemon brings sharpness, more orange brings sweetness.
- Add the leaf and flower
Add petitgrain and the neroli base. You will notice the accord deepening and moving towards a "cologne" character.
- Make the aromatic touch
Add rosemary a little at a time; too much turns the accord into a kitchen smell.
- Finish with the extenders
Add linalool, linalyl acetate and Hedione.
- Use at once, or store well
Store the accord in a bottle filled to the top, dark-coloured or aluminium, somewhere cool. If it will be kept for long, consider adding an antioxidant.
Variations and the Longevity Problem
The known weakness of a citrus accord is its lifespan: it is made of the most volatile raw materials and disappears from the skin in a short time. This is not a fault but the nature of the material. You cannot solve longevity by raising the concentration; you have to change the structure.
Longer lasting: Raise Hedione, and add musk (such as Ethylene Brassylate) and a transparent woody molecule (Iso E Super) to the base. The citrus still evaporates, but a clean, fresh trail remains behind it. Citrus-character synthetics such as dihydromyrcenol also extend the freshness.
Greener and more bitter: Raise petitgrain, add grapefruit or bitter orange oil. A drier, more grown-up character emerges.
Sweeter and fruitier: Raise orange and mandarin oil, reduce lemon. You get a childlike, cheerful citrus.
More floral: Raise the neroli base and linalyl acetate; add a small dose of a jasmine effect. The accord shifts from cologne towards a floral-citrus perfume.
IFRA, Safety and Frequently Asked Questions
Safety in a citrus accord comes under two headings. Phototoxicity: cold-pressed bergamot, lemon and some other citrus oils contain components (furocoumarins) that can cause staining and irritation on the skin in sunlight. In products that contact the skin, bergapten-free (FCF) bergamot and qualities that comply with IFRA limits are used. Being natural does not make these oils safe. Allergens: limonene, linalool and citral are allergens requiring declaration and are present at high levels in citrus oils; do the label calculation.
Oxidised citrus oil both smells bad and sensitises the skin more. In this accord, freshness is not a matter of quality but of safety.
Why does a citrus accord evaporate so quickly?
What is the difference between cologne and perfume?
Does bergamot stain the skin in the sun?
What is petitgrain?
Are neroli and orange blossom the same thing?
My citrus oil smells of turpentine; can I use it?
Which notes does a citrus accord go with?
How much of this accord is used in a lemon cologne?
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