How to Work in Dilution: A Beginner's Guide to Diluting Perfume Materials

At a glance

• Dilute almost everything before you smell it or use it in a formula.
• Start with perfumer's alcohol as your solvent.
• Make most materials at 10%: 1 g of material + 9 g of solvent.
• Go to 1% or 0.1% for anything that still takes over at 10%.
• Weigh, don't count drops. A 0.01 g scale is your most important tool.
• Label every bottle: material, strength, solvent, date and supplier.
• Do the maths: 1 g of a 10% dilution is only 0.1 g of material.

What does "working in dilution" mean?

Working in dilution means mixing each fragrance material with an odourless solvent before you smell it or use it in a formula. A 10% dilution is 1 part material to 9 parts solvent, so 10% of the finished mixture is the material itself.

Most perfumers keep a working set of diluted materials, usually at 10%, and build formulas from those rather than from the neat (undiluted) bottles.

Why perfumers dilute their materials

• You smell the material properly. Many materials smell harsh, flat or even unpleasant at full strength. Diluted, they open up and show their real character. Indole is the classic example: neat it smells faecal, with a mothball edge, but at 1% or less it reads as white flowers.
• Your nose lasts longer. Sniffing neat materials tires your nose quickly, so you stop being able to judge what you are smelling.
• You can measure tiny amounts accurately. A formula might need 0.02 g of a powerful material. Most scales can't weigh that reliably, but 0.2 g of a 10% dilution is easy.
• Mistakes cost less. An error made with diluted material is smaller and easier to correct, and you use up less of an expensive material while learning.
• It is safer to handle. Many materials are skin and eye irritants at full strength. Diluting reduces the risk of a spill or splash doing harm. Always check the Safety Data Sheet (SDS) for each material.

Choosing a solvent

For an alcohol-based perfume, dilute in perfumer's alcohol or DPG. Use the same solvent your finished perfume will be made in where you can, so nothing is left out of balance at the end.

If you are just starting out, I recommend perfumer's alcohol for your working dilutions. Most perfumes end up in an alcohol base anyway, so your trials smell the way the finished perfume will, nothing extra ends up in the bottle, and it is the cheapest option. Just keep the caps tight so it doesn't evaporate.

Which dilution strength should you use?

Start with 10% for almost everything, then go weaker for materials that still overpower at that level. The stronger the smell, the weaker the dilution.

These are starting points, not rules. If a material still smells sharp or loud on a strip after a few minutes, make a weaker dilution. Check the label too: some materials, like Ambermax 50% or Geosmin 1%, are already sold pre-diluted, so the percentage on the bottle is your starting point.

How to make a 10% dilution, step by step

You will need a digital scale that reads to 0.01 g, a clean glass bottle with a tight lid, a disposable pipette, your solvent, gloves and a label.

1. Put on gloves and work somewhere well ventilated, away from flames.
2. Place the empty bottle on the scale and press tare so it reads 0.00 g.
3. Add the material. For 10 g of dilution, add 1.00 g of the material with a pipette.
4. Tare again, then add 9.00 g of solvent. The scale now reads 9.00 g, and the bottle holds 10 g in total.
5. Cap and shake well. Crystals and thick resins can take a few hours to dissolve; standing the bottle in warm (not hot) water helps.
6. Label it straight away with the material, the strength, the solvent, the date and the supplier.
7. Let it rest for a day or two before you judge it. Many materials smell rounder once fully blended.

The formula behind it: amount of material = total weight wanted × strength. For 20 g at 10%, that is 20 × 0.10 = 2 g of material and 18 g of solvent.

Want to start without gathering everything separately? My Essential Dilution Starter puts what you need to begin working in dilution in one kit, with DPG as the solvent. If you are making roll-on oil perfumes, there is also a version with jojoba oil.

Making weaker dilutions from a stronger one

To get very weak dilutions accurately, make them in steps from a stronger one. This is called serial dilution, and it avoids trying to weigh impossibly small amounts of neat material.

• 10% to 1%: 1 g of your 10% dilution + 9 g of solvent = 10 g at 1%.
• 1% to 0.1%: 1 g of your 1% dilution + 9 g of solvent = 10 g at 0.1%.

Each step makes the dilution ten times weaker. Use the same solvent at every step so you know exactly what is in the bottle.

Learning this the hard way

I used to assume 10% was low enough for anything. Ginger essential oil and Calone proved me wrong.

At 10%, a drop of ginger took over every trial I put it in. Its sharp, hot spice sat on top of everything else and I couldn't hear the rest of the blend. Calone was even worse: a tiny amount of a 10% dilution turned whole formulas into a wall of watery melon.

Taking both down to 1%, and Calone further still, changed everything. They became accents I could actually control instead of materials I was fighting. Now if a material dominates a trial at 10%, I don't keep adding less of it; I make a weaker dilution.

Why weigh instead of counting drops?

Weigh everything. Drops vary in size from one material to the next, because thick materials form bigger drops than thin ones, and different pipettes give different drops again. A formula written in drops can't be repeated reliably.

Working by weight means your 10% is truly 10%, and a formula you love can be scaled up or remade months later with the same result. A jewellery scale that reads to 0.01 g is inexpensive and is the best tool a beginner can buy.

Using dilutions in a formula

When you build a formula from dilutions, record two numbers for every material: the weight of dilution you added, and the real amount of material that weight contains. The real amount is what tells you the true balance of your blend.

Real amount of material = weight of dilution × strength

Here is a small fresh, watery floral trial built from dilutions in perfumer's alcohol:

The bottle weighs 10 g, but only 0.955 g of it is fragrance material; the other 9.045 g is alcohol. The last column shows the true proportions. That is the version to use if you remake the blend from neat materials or scale it up for a finished perfume. (Shares are rounded, so they add to 99.9%.)

Look at the Calone line. A neat formula would need just 0.005 g of it, which no hobby scale can measure. That is dilution doing its job.

Labelling and storing your dilutions

Label every bottle the moment you make it. Unlabelled dilutions are the most common source of confusion in a beginner's collection. Each label should show:

• Material name and strength
• Solvent and date made
• Supplier, since the same material can smell different from one supplier to the next, and you will want to reorder the exact one

For example:

Vertenex 10%
Ethanol 05/10/2026
The Parfum Apothecary

Store dilutions in amber or cobalt glass with tight caps, upright, somewhere cool and away from direct light. Most keep well for many months. Citrus oils and some aldehydes change faster, so smell them before use and remake when they turn flat or sour.

Common beginner mistakes

• Smelling straight from the bottle. Dip a smelling strip in the dilution instead, and wave it gently a few centimetres from your nose.
• Judging too fast. Smell the strip again after 10 minutes, an hour and the next day. The heart and base of a material often surprise you.
• Forgetting the dilution in the maths. Adding 1 g of a 10% dilution is 0.1 g of material, not 1 g. Always record the real amount.
• Mixing solvents. A formula made from some DPG and some alcohol dilutions is harder to repeat. Pick one solvent for your working set.
• Diluting by volume. Millilitres and drops are unreliable for fragrance work. Use a scale.
• Skipping the label. You will not remember which clear liquid is which in three weeks.

Frequently asked questions

What does a 10% dilution mean in perfumery?

It means 10% of the mixture by weight is the fragrance material and 90% is solvent. For example, 1 g of material in 9 g of perfumer's alcohol.

What is the best solvent for diluting perfume materials?

Perfumer's alcohol is the industry standard for alcohol-based perfumes. It is also the best place for a beginner to start, because most finished perfumes are alcohol-based and it is the cheapest solvent. DPG, DEP and TEC are good alternatives if you want dilutions that don't evaporate.

Can I dilute fragrance materials in water?

No. Most fragrance materials don't dissolve in water, so they separate out. Use alcohol, DPG, DEP, TEC or an oil instead.

Do all fragrance materials need to be diluted, or just aroma molecules?

All of them. Essential oils and absolutes need diluting too, and 10% is generally the right strength for both. Working in dilution makes experimenting cheaper and easier, whatever the material. The main exceptions are a few soft aroma molecules, like Iso E Super and Hedione, which can be used at 50% or neat.

How long do perfume dilutions last?

Most last many months when sealed and stored cool and dark. Citrus oils and aldehydes fade sooner, so smell them before use.

How strong should my finished perfume be?

As a rough guide, an eau de toilette holds around 5 to 15% fragrance concentrate and an eau de parfum around 15 to 20%. Check the IFRA limits for each material in your formula before you finalise it.

Got a question about a specific material? Email me at alex@theparfumapothecary.com.

Alex