Beginner perfumer · 31
"Workhorse" is measurable: a report card across fourteen genres of 954 formulas
· 27 min read
Someone asked which materials count as workhorses — "components like Hedione or IES, which can make composition better without being too obvious". That definition has two conditions, and both can be measured. I sorted 954 public formulas into fourteen genres by title, then counted how many genres each material appears in and how concentrated it is in its biggest one. Patchouli oil and bergaptene-reduced bergamot span all fourteen with only 19.9% and 20.2% in their largest genre. Hedione's floral share is 35.4%, exactly matching the corpus's own floral baseline of 35.4%. Fifteen of the forum's sixteen scoreable nominations hold up.
Someone asked a well-defined question on r/DIYfragrance:
"I mean components like Hedione or IES — workhorses, which can make composition better without being too obvious? Maybe, salicylates for floral scents? Or Muscenone Delta for musks, for example."
Twelve replies, each with its own list.
And that definition hides two conditions, both of which can be measured.
- "make composition better" → gets used often
- "without being too obvious" → not tied to one genre
The second condition is the interesting one, and it is something I had not computed before.
The short version
- I sorted the 954 public formulas into fourteen genres by title (floral, fruity, citrus, woody, chypre, fougère, oriental/amber, musk, green/herbal, gourmand, marine, spicy, leather/tobacco, functional). 752 of them (78.8%) get at least one label.
- The two materials spanning all fourteen with the lowest concentration in any single genre are patchouli oil (19.9%) and bergaptene-reduced bergamot (20.2%).
- The corpus's own floral baseline is 35.4%. A material's floral share has to be compared against that, not against zero.
- Hedione's floral share is exactly 35.4%. Identical to the baseline — it appears in each genre in proportion to how much of that genre this corpus contains. That is the purest form of "workhorse".
- Of the forum's nominations, sixteen had enough sample to score, and fifteen hold up.
- The one the data pushes back on is hydroxycitronellal: 161 formulas, 13 genres, which looks like a workhorse — but its floral share is 54.7%, far above baseline. It is a specialist in a workhorse's coat.
About 9 minutes.
Turning "not obvious" into a number
The method first, because everything rests on it.
Each of those 954 formulas has a title — "floral fruity fragrance", "chypre perfume base", "lily of the valley type", "powder detergent perfume". I sorted titles into fourteen genres by keyword, and a formula can belong to several ("fruity floral" counts as both).
| Figure | |
|---|---|
| Formulas | 954 |
| Getting at least one label | 752 (78.8%) |
| Total labels | 1,066 |
| Floral labels as a share of all labels | 35.4% |
That last row is the most important number here.
Because this corpus is heavy on florals, every material's floral share will look high. So "40% of this material's appearances are in florals" means nothing on its own. What matters is the distance from that 35.4% baseline.
- Well below 35.4% → it spreads wider than the corpus itself. That is a workhorse.
- Well above 35.4% → it concentrates in florals more than the corpus does. That is a specialist.
The ones spanning all fourteen
Among materials appearing in at least 20 formulas with enough labels to score, fifteen span all fourteen genres. Sorted by largest-genre share, lowest first:
| Material | Formulas | Genres | Largest genre | Median dose |
|---|---|---|---|---|
| patchouli oil | 132 | 14/14 | 19.9% | 3.45% |
| bergamot, bergaptene reduced | 132 | 14/14 | 20.2% | 10.00% |
| ethyl vanillin | 80 | 14/14 | 25.2% | 0.50% |
| vanillin | 137 | 14/14 | 28.9% | 1.00% |
| coumarin | 225 | 14/14 | 29.7% | 2.34% |
| alpha-hexyl cinnamaldehyde | 157 | 14/14 | 32.4% | 8.00% |
| Hedione | 165 | 14/14 | 35.4% | 7.00% |
| beta-ionone | 107 | 14/14 | 35.5% | 1.94% |
| linalyl acetate | 207 | 14/14 | 36.3% | 5.56% |
| eugenol | 161 | 14/14 | 40.5% | 1.70% |
| linalool | 338 | 14/14 | 41.4% | 5.93% |
| citronellol | 220 | 14/14 | 42.8% | 5.94% |
| benzyl salicylate | 159 | 14/14 | 42.8% | 9.47% |
| benzyl acetate | 317 | 14/14 | 45.5% | 5.00% |
| phenethyl alcohol | 274 | 14/14 | 51.1% | 10.00% |
The top six sit below the baseline. They spread wider than the corpus itself.
That patchouli and bergamot lead is worth a pause.
They are naturals. Most of what the thread named is synthetic — Hedione, IES, Habanolide, Muscenone, Florol — and the two most general-purpose materials in the corpus are essential oils. One is the base of a chypre and the other the head of a cologne, and both turn up in gourmand, musk, functional and marine work alike.
Two people in the thread did name them. middleaged_mpd wrote that patchouli and labdanum are "just so versatile", and Public-Ideal-5166's list includes bergamot. The data agrees with them.
Hedione lands exactly on the baseline
The first example the poster gave was Hedione.
Its floral share is 35.4%. The corpus's floral baseline is 35.4%.
The same number.
What that coincidence means is worth spelling out: Hedione turns up across genres in the same proportions as this corpus works in those genres. No preference and no aversion. Whatever is being made, it shows up in it.
That is the cleanest definition of the word.
(We've covered Hedione. This adds its position in the corpus: 165 formulas, median 7.00%, distributed like the corpus itself.)
The forum's report card
The sixteen nominations with enough sample to score:
| Nomination | Formulas | Genres | Largest genre | Verdict |
|---|---|---|---|---|
| Cashmeran | 32 | 13/14 | 15.9% | ✓ most evenly spread of all |
| patchouli oil | 132 | 14/14 | 19.9% | ✓ |
| bergamot | 132 | 14/14 | 20.2% | ✓ |
| isoamyl salicylate | 47 | 13/14 | 24.5% | ✓ |
| Ambroxan | 31 | 10/14 | 25.6% | ✓ |
| Iso E Super | 104 | 13/14 | 30.5% | ✓ |
| alpha-hexyl cinnamaldehyde | 157 | 14/14 | 32.4% | ✓ |
| Vertofix | 50 | 12/14 | 33.9% | ✓ |
| ethyl linalool | 38 | 12/14 | 34.4% | ✓ |
| Hedione | 165 | 14/14 | 35.4% | ✓ dead on baseline |
| raspberry ketone | 45 | 12/14 | 35.8% | ✓ only one whose top genre is not floral |
| linalool | 338 | 14/14 | 41.4% | ✓ |
| Habanolide | 35 | 10/14 | 30.8% | ✓ |
| Florol | 24 | 9/14 | 40.0% | △ narrower |
| Mayol | 21 | 6/14 | 35.3% | △ only six genres |
| hydroxycitronellal | 161 | 13/14 | 54.7% | ✗ specialist |
Fifteen of sixteen stand.
Cashmeran's 15.9% is the lowest on the whole table, spreading wider than patchouli — it appears in only 32 formulas, and those 32 are spread almost flat across fourteen genres. We've covered Cashmeran, and this number is its best defence.
Raspberry ketone is the only nomination whose top genre is not floral (it is fruity, at 35.8%). middleaged_mpd described it as useful "in white florals, with rose, with lactonics, for enhancing leather… and with other fruit accords" — spanning 12 genres supports that description.
The one that got pushed back
Hydroxycitronellal looks exactly like a workhorse: 161 formulas, 13 genres, one of the EU's 26 declarable allergens, everybody has some.
But its floral share is 54.7%, 1.55 times the baseline.
It appears a great deal, and it appears in florals. It is a structural material for lily of the valley, and there is a lot of lily of the valley in this corpus.
This does not make middleaged_mpd wrong. What they said was that hydroxycitronellal with ethyl linalool covers the smell of ethanol well — a specific use rather than a claim about versatility. And ethyl linalool scores 12/14 at 34.4%, genuinely general-purpose.
The lesson is that "everyone uses it" and "it goes with anything" are different statements.
Why workhorses have to exist
This connects to an experiment we cited last round.
Weiss and colleagues found in 2012 that at about 30 equal-intensity components spanning odour space, most mixtures smell alike, even sharing no component.
The way formulas escape that regime is by being wildly unequal by weight — the median formula's top three carry 54.7%.
Workhorse materials are what holds that inequality up.
Phenethyl alcohol at a median of 10.00%, hexyl cinnamal at 8.00%, benzyl salicylate at 9.47% — those three together are already more than a quarter of a formula. And what they share is: all fourteen genres, a low largest-genre share, and a high dose.
"Not obvious" and "used in quantity" do not conflict; they are two sides of one thing. A material can go in at 10% without dominating precisely because it does not pull the formula in any particular direction.
Specialists are not a defect
The opposite list is useful too:
| Material | Formulas | Genres | Largest genre |
|---|---|---|---|
| cinnamic alcohol | 98 | 11/14 | 71.9% floral |
| ethyl acetate | 20 | 4/14 | 71.4% fruity |
| benzyl alcohol | 43 | 5/14 | 69.4% floral |
| jasmine absolute | 23 | 3/14 | 66.7% floral |
| phenylacetaldehyde | 57 | 9/14 | 66.1% floral |
| rhodinol | 39 | 9/14 | 64.9% floral |
These are not worse materials. They are the materials that define genres.
Jasmine absolute spans three genres because it is jasmine. High versatility means a material will not push a formula anywhere; low versatility means it will. And sometimes pushing is the job.
The two lists serve different purposes when you are buying: the workhorse list decides how usable your palette is, and the specialist list decides what you can make with it.
(Material guide #72 covers the phenylacetaldehyde on that list — one of the most concentrated specialists in the corpus, for a good reason.)
What this doesn't establish
The genre classification is keyword matching against titles, not human judgement. A title containing "rose" counts as floral and one containing "woody" counts as woody. That misfires: "rosewood" gets counted as floral when it is woody. I did not check all 752 by hand.
21.2% of formulas get no label at all (titles like "fragrance composition" carry no information). Those 202 are absent from the breadth statistics entirely, and they are not necessarily missing at random.
Genre count saturates at 14. Fifteen materials scored 14/14, so that column cannot separate them — which is why the largest-genre share is the second metric.
The 35.4% baseline is a share of labels, not of formulas. A formula can carry several labels, so it does not mean "35.4% of formulas are floral".
Sample sizes differ enormously. Linalool has 338 formulas and Mayol has 21. Mayol's 6/14 could be a small-sample artefact rather than genuine narrowness. That is what the △ marks.
The corpus's vintage bias matters especially here. 74% comes from patents and published sources, so newer materials — Habanolide (35), Muscenone (4), Florol (24) — all have small samples, and they may well be more common in current practice than these records show. When the forum names them and the corpus cannot supply strong evidence, that gap belongs to the corpus rather than to the people naming them.
"Hedione lands exactly on the baseline" is a lovely coincidence, and it is a coincidence. Both numbers are rounded to one decimal place, and a different classification scheme need not keep them equal. I cannot claim that as a robust result.
Weiss's conditions — equal intensity, spanning odour space — are met by no perfume, as the previous piece set out. I cite it to show that inequality does work, not to predict anything about a formula.
References
T. Weiss, K. Snitz, A. Yablonka, R. M. Khan, D. Gafsou, E. Schneidman, N. Sobel, Perceptual convergence of multi-component mixtures in olfaction implies an olfactory white, Proceedings of the National Academy of Sciences, 109(49), 19959-19964 (2012). PMID 23169632. doi:10.1073/pnas.1208110109
Related: he asked whether one or two would do, how big is the palette, buying by frequency, the starter palette map.