Dilutions: why 10% solves problems you have not had yet
Some of the best materials in perfumery are dosed at two thousandths of a percent. No scale you can afford will weigh that — and you do not need one.
Sooner or later you buy a material whose working dose is written like this: 0.002 to 0.2 per cent. That is Ambrocenide, and it is not unusual. At the bottom of that range, a 10 g trial wants 0.0002 g of it — two ten-thousandths of a gram. A 0.001 g scale, which is already the good kind, cannot see it. It will read zero, then zero, then suddenly 0.001, which is five times your intended dose.
The answer is not a better scale. It is to stop weighing the material and start weighing a solution of it.
The arithmetic, which is all of it
Dissolve one part of the material in nine parts of a solvent and you have a 10 per cent dilution. Every gram of that solution contains 0.1 g of material. So:
- To place 0.02 g of neat material, weigh 0.2 g of the 10 % solution.
- To place 0.0002 g, go further — a 1 % dilution, and weigh 0.02 g of it.
Multiply by ten, weigh, and the number lands in the middle of the range your scale is good at instead of at the edge where it is guessing. That is the whole idea.
What to dilute
Three tests, and one is usually enough:
- The dose says so. If the maximum working dose is below about 1 %, dilute. Eugenol runs 0.02–1 %. Oakmoss absolute runs 0.05–1.5 %. Ambrocenide runs 0.002–0.2 %.
- It is solid or nearly solid. Coumarin, vanillin and most of the crystalline materials cannot be pipetted at all until they are in solution.
- You cannot smell past it. Neat indole smells of nothing you want. At 1 % it smells of jasmine. You are not evaluating a material until you are evaluating it at a sane strength.
What to dilute in
| Solvent | Good for | Watch for |
|---|---|---|
| Dipropylene glycol (DPG) | Almost everything. Odourless, does not evaporate, keeps for years. | It stays in the finished perfume — at 10 % dilution, nine tenths of what you weighed is solvent. |
| Perfumer’s alcohol | Anything you intend to spray, and anything you are judging on a blotter. | It evaporates, so an open bottle drifts stronger over months. |
| Isopropyl myristate (IPM) | Oil-based work, and materials that will not sit in DPG. | Faintly oily on the skin; not for everything. |
For a bench you are learning on, DPG for storage and alcohol for evaluation covers almost every case. Do not mix the two in one bottle.
The mistake everybody makes once
You write 0.2 — Ambrocenide in your notebook. Six weeks later you
scale it up, reach for the neat bottle, and put in ten times what the formula meant.
The blend is ruined and, worse, you do not know why.
There is one cure and it is boring: the strength is part of the name. Never write "Ambrocenide". Write "Ambrocenide 10% DPG". Put it on the bottle, put it in the formula, put it in the notebook. A dilution with no strength written on it is not a material, it is a mystery, and the only safe thing to do with a mystery bottle is pour it away.
Date it as well. Alcohol dilutions concentrate slowly as the solvent leaves; a two-year-old bottle is not the strength on the label.
In the Crafted Scent application, the Inventory holds what you actually own — including dilutions, at the strength you made them — while the bench works in the concentrate. So a formula stays a statement about the perfume rather than about your shelf, and the Weigh-out still tells you what to put on the scale.
Open the inventory →How to make one, in five minutes
- Tare a small glass bottle on the scale.
- Add 1 g of the material. Solids first — they need the solvent to find them, not the other way round.
- Add 9 g of solvent. Cap it, and leave it alone.
- Crystalline materials need warmth and patience. Stand the bottle in warm water, not on a flame, and give it hours rather than minutes.
- Label: name, strength, solvent, date. All four.
Ten grams is enough. At 10 % that is a gram of material, and a gram of most things is a very long time at 0.2 % of a 10 g trial — about five hundred trials, if you are counting.
What it actually buys you
Precision is only the first thing. The second is that dilution makes materials legible. Most powerful aroma chemicals smell wrong neat — flat, harsh, chemical, nothing like their reputation. At 1 or 10 % they open out and you can finally hear what everyone has been talking about. Perfumers do not dilute because the scale is bad. They dilute because that is the strength at which the material tells the truth.