Short answer
To create a perfume formula, start with a one-paragraph brief, build a small core accord by ratio trials, then add supporting materials in measured steps — all by weight, with every dilution recorded. Make 5–20 g trials, let each rest before judging it, compare it with the previous trial, and change one thing at a time. Write down every version, including the ones you reject; the record is what lets you make the same perfume again.
Step 1: write a brief, even for yourself
A formula without an intention tends to drift. Before weighing anything, write a few lines:
- What should it smell like, in plain words? ("A dry, transparent woody scent with a bright citrus opening.")
- What product is it for? A spray perfume, an oil, a candle, a lotion — each has different technical limits and different safety categories.
- What strength? An eau de parfum around 15–20% is a common starting point for a spray.
- Any constraints: materials to avoid, cost per gram, natural-only, a deadline.
For client work, the brief is a document in its own right — see how to write a fragrance brief.
Step 2: smell your materials properly
You cannot formulate with materials you do not know. Smell each candidate on a labeled blotter at a sensible dilution (often 10% or 1%), and smell it again after an hour and after several hours. Note its character, strength and how long it lasts. Materials that seem pleasant neat can be harsh in a blend; others that seem dull alone become essential in combination.
Group what you smell by role. The top, middle and base notes pyramid is a reasonable first sort: what is noticeable at the start, what forms the heart, and what remains hours later.
Step 3: build a core accord
Start with two or three materials that carry the idea. Make a series of small blends at different ratios — 1:1, 2:1, 3:1, 1:2, 1:3 — weighed, labeled and smelled side by side. Pick the ratio that is most convincing and refine around it. That small blend is your accord, and it becomes the backbone of the formula. Fragrance accords explained covers the method in detail.
Step 4: write the first full formula
Add materials around the accord to give it an opening, a fuller heart and a base, in deliberate amounts. Keep the first version short — eight to fifteen materials is plenty — so that every material's effect can be smelled. Write it in parts per thousand or percentages so the total is a fixed number and the proportions are easy to read.
| Material | Role | Parts |
|---|---|---|
| Bergamot oil (furocoumarin-free) | Bright opening | 150 |
| Linalool | Fresh floral lift, bridges citrus to heart | 100 |
| Hedione | Transparent floral volume | 250 |
| Iso E Super | Dry, woody, diffusive core | 200 |
| Cedarwood oil (Virginia) | Pencil-shaving wood | 100 |
| Galaxolide 50% | Clean musk base | 100 |
| Ambroxan 10% | Ambery, mineral warmth | 80 |
| Vanillin 10% | Soft sweetness | 20 |
| Total | 1000 |
Note the dilutions in the names: 80 parts of "Ambroxan 10%" is 8 parts of Ambroxan. If you prefer to keep strong materials as solutions, how to dilute aroma chemicals explains how to make and record them. Before using any formula — this one included — check each material's IFRA limit for your product category; several common materials, including citrus oils, are restricted.
Step 5: make a small trial, accurately
Convert the formula to grams for a small batch — at 10 g, each part is 0.01 g, so 150 parts is 1.50 g. Use a balance that reads to at least 0.01 g, weigh into a clean glass vial, and write down the actual weights as you go. Label the vial with the formula name, version and date. If you will judge it as a finished perfume, dilute a portion in alcohol at your target strength.
Step 6: wait, then evaluate
A trial judged the moment it is mixed is not the perfume it will become. Give it at least a few days before serious evaluation, then smell it on blotters and skin at set times — the opening, after 30 minutes, after a few hours, the next day — next to the previous trial. Write down what you smell, not just whether you like it. How to evaluate a perfume formula has a method.
Step 7: change one thing, and record it
Decide what most needs to change, change it, and make a new version. If you change four materials at once and the result is better, you will not know which change helped. Each version gets a number, and the record says what changed and why. How to adjust and refine a perfume formula covers step sizes and keeping the total consistent.
Step 8: keep a record you could hand to someone else
The test of a formula record is whether someone else could remake the trial from it. That means: materials named specifically (supplier and grade where it matters), every dilution recorded, weights in grams, the version, the date, and notes on what you observed. A perfume formula template gives you a layout. Whether you keep it on paper, in a spreadsheet or in software like RUŌOD Lab, the discipline is the same.
For the broader picture — materials, structure, safety and records — see perfume formulation explained.
Frequently asked questions
How big should a first trial be?
Big enough to weigh accurately and to smell properly: 5–20 g of concentrate is common. Smaller trials save material but magnify weighing errors in the smallest rows.
Should I copy a published formula to start?
Remaking a published formula is a good way to learn how materials work together, as long as you treat it as study. Check its materials against current IFRA restrictions, which may have changed since it was written.
When is a formula finished?
When it meets the brief, has been evaluated over enough time and conditions to trust, and has been checked for safety and compliance for its intended use. Mark that version as approved and lock it against accidental edits.
Written and reviewed by the RUŌOD Lab team. This article is general education about perfume formulation and record-keeping; it is not legal, regulatory or safety advice, and the examples are illustrations, not validated commercial formulas. How we write and check these guides.