Someone posted a 36-line crème brûlée formula, and half of it is solvent

Someone on r/DIYfragrance posted the whole of what they are working on, in French:

"Hello everyone! I wanted to share a little formula I'm working on at the moment."

"Being a big gourmande (laughs), I love crème brûlée. I had one at an excellent restaurant a few days ago and thought: why not try to recreate that sensation as a perfume?"

"I obviously wanted a vanilla and caramelised note, but also a texture, a 'BRRRRRR' texture, like the feeling of crushed cereal grains."

Then the full 36-line formula, totalling 1000.

This formula deserves serious treatment, because it includes the line most people leave out.

The short version

• Multiplying every line's dilution strength back out: 503.6 parts neat fragrance material (50.4%), 496.4 parts solvent (49.6%).
• Of the solvent, TEC accounts for 405 parts, of which 280 are written as the formula's own first line and 125 are carried in by the 10% and 1% dilutions. DPG is 91 parts.
• The smallest line converts to 0.05 parts neat, 0.005% of the formula — five parts in a hundred thousand.
• To weigh that neat at ten scale divisions (roughly 10% precision), a 0.001 g scale needs a 200 g batch.
• Weighing the pre-made dilution instead needs a 10 g batch. That is what dilutions are for, and it matters more than any piece of equipment.
• And as for the burnt sugar on top of a crème brûlée, two studies of entirely different foods point at the same two molecules: sotolon and furaneol. Both are readily obtainable, with 41 and 101 suppliers respectively. (This piece originally said the database had no record of them. That was wrong; corrected 28 August 2026, explanation below.)

That TEC line

The formula's first line is:

TEC 280

TEC is triethyl citrate, a diluent, covered in this series as material guide #84. She lists the diluent as a line of the formula, and it is the largest line in it.

Most formulas circulating online do not do that. They list material A at so many parts and material B at so many, totalling 100 or 1000, and the diluent vanishes outside the arithmetic. The reader is then left not knowing how strong the result is.

Broken out:

Class	Parts	Share
Neat fragrance material	503.60	50.4%
TEC (the written line)	280.00	28.0%
TEC (carried in by dilutions)	125.10	12.5%
DPG (carried in by dilutions)	91.30	9.1%
Total solvent	496.40	49.6%

Of these 1000 parts, 496 are not fragrance material.

To be clear: that is neither waste nor an error. It is the actual composition of a concentrate. When you add it to alcohol, the fragrance load is calculated on these 1000 parts, so the real material concentration is half what you think. Label it "20% fragrance load" and the finished perfume holds 10% neat material.

And had she not written that TEC 280 line, you would read this as a 720-part concentrate, dose it at 20%, and end up with something 39% stronger than hers.

The smallest line sets your batch size

The formula's last two lines are:

Maple lactone 1% DPG　　5 Sulfurol 1% DPG　　　　5

Listed as 5 parts, but that is a 1% dilution. Neat, it is 0.05 parts.

In a 1000-part formula, 0.05 parts is 0.005%.

Convert that to weight on a scale. Say you have a 0.001 g (1 mg) jeweller's scale:

Approach	Weight to hit	Batch needed
Neat maple lactone, just registering (1 division)	0.001 g	20 g
Neat maple lactone, at 10% precision (10 divisions)	0.010 g	200 g
The 1% dilution, at 10% precision	0.010 g	10 g

That is what dilutions do. Same scale, same precision requirement: 200 g of batch neat, 10 g using dilutions.

A factor of twenty.

And 200 g of concentrate is, at a 20% fragrance load, a litre of perfume. Nobody making their first formula wants a litre. So the answer is not a better scale; it is making the dilutions first.

Another thread asked the other half of the same question. A beginner wrote that his scale's smallest division is 0.03 g and asked whether to buy calibration weights. Running the same formula on his scale:

	Batch needed
0.03 g scale, weighing neat, 10% precision	6,000 g
0.03 g scale, weighing dilutions, 10% precision	300 g

Even with everything pre-diluted, that scale still needs a 300 g batch. This 36-line formula cannot be made on a 0.03 g scale, and no spatula, weighing boat or calibration weight changes that.

The equipment people recommended in that thread — spatula, weighing boats, 0.2 mL pipettes, tray, label printer — are all useful, and the first and last solve the same problem. Once you have dozens of dilution bottles, you need to be able to scoop, pour and label.

Dilutions are not an advanced technique; they are the precondition for that equipment list.

Thirty-six lines, and their shape

The distribution of parts is worth a look on its own:

Band	Lines
100 parts and above	2 (TEC 280, ethylene brassylate 115)
30–99 parts	6 (ethyl vanillin 85, veratraldehyde 85, Musc R1 60, heliotropin 35, ethyl maltol 30, Vanilline Signature 30)
10–29 parts	14
1–9 parts	14

Half the lines are at 9 parts or fewer, and almost all of those are 10% or 1% dilutions. It is a common shape: a few materials carrying the weight and a long list doing the modification.

And the modifying half is exactly the half that forces you to keep dilutions.

The chemistry of crème brûlée: two papers, the same two molecules

One of the things she wanted was burnt sugar. That has a name: the Maillard reaction and caramelisation.

Kim and colleagues, 2013, in Meat Science, applied solid-phase microextraction gas chromatography-olfactometry (SPME-GCO) and aroma extract dilution analysis (AEDA) to the potent odorants in cooked beef extracts. The Maillard reaction volatiles they list as necessary for typical cooked beef flavour include:

Compound	The paper's odour attribute
2-methyl-3-furanthiol and two others	Meaty
2-furanmethanethiol	Roasty
4-hydroxy-2,5-dimethyl-3(2H)-furanone (furaneol)	Caramel-like
3-(methylthio)propanal (methional)	Baked potato-like
3-hydroxy-4,5-dimethyl-2(5H)-furanone (sotolon)	Spicy

Fan and colleagues, 2020, in Food Research International, studied something completely unrelated: Tibetan Qingke Jiu, a barley liquor. Sensory evaluation found it had fruity, cooked potato, honey, sour, sweet and caramel-like aroma. AEDA with GC-MS identified 66 aroma compounds with flavour dilution factors from 4 to 2048; quantitation by four methods found 17 odorants above their thresholds. By odour activity value, those potentially important to the overall profile included phenylacetaldehyde, β-phenylethanol, ethyl phenylacetate, sotolon, furaneol, methional, methionol, γ-nonalactone and β-damascenone.

Cooked beef and barley liquor, two unrelated things, and the same two molecules named for the caramel side.

Sotolon and furaneol are products of the Maillard reaction and caramelisation. The blowtorched sugar on a crème brûlée and a seared steak are the same reaction.

You can buy those two (this section is corrected)

At this point the answer looks simple: buy sotolon and furaneol. And the answer really is that simple. I searched wrong the first time.

The original version of this piece said the database had no record of sotolon, that furaneol had a single supplier, and that maple lactone had no record, and inferred from that that the author "takes the route you can buy". All three lookups were wrong, so the inference does not hold either.

The correct result:

Molecule	Name in the database	CAS	Suppliers
Sotolon	caramel furanone	28664-35-9	41
Furaneol	strawberry furanone	3658-77-3	101
Maple lactone	cyclotene	765-70-8	72
Abhexon	maple furanone	698-10-2	67
Maltol	maltol	118-71-8	107
Ethyl maltol	ethyl maltol	4940-11-8	75
Sulfurol	sulfurol	137-00-8	105

The three materials I reported as unobtainable have 41, 101 and 72 suppliers. Furaneol is easier to buy than everything here except maltol.

The cause of the error is specific: I searched the database's name column using chemical names. This database files flavour materials under marketing names — caramel furanone, strawberry furanone, maple furanone — with the chemical name in the synonym field and the word sotolon sitting in the notes field. My query was name LIKE '%sotolon%', which never reaches the notes.

Not matching is not the same as not existing, and I wrote the first as the second.

The irony is that this series measured exactly this phenomenon in article #41: of the 120 most-used materials, 41 could not be looked up, and every missing one was a trade name. I wrote that, and fell into the same hole the following round — in the opposite direction. There, formulas used trade names and the database used chemical names; here, I used chemical names and the database used trade names.

Corrected, this section's conclusion reverses. The author uses ethyl maltol, Sulfurol and maple lactone (she writes "lactone d'érable") not because sotolon is unobtainable, but because those are the stock materials for this direction, and maple lactone belongs to exactly the family the papers describe. Her choices agree with the literature rather than routing around it.

This round's material guide covers sotolon itself, including why the database files it under another name.

The analysis I did not run this round

By this series' habit, there should now be a section counting how often these materials appear in gourmand formulas. I ran it, and decided not to publish it.

The corpus holds only 12 formulas with vanilla, gourmand, caramel, chocolate, coffee, honey or almond in the title.

Last round, with leather at 9, I returned a blank and wrote down a rule: reporting a ratio on an inadequate sample invites the reader to treat it as a result. Twelve and nine are the same order.

Some pretty numbers did come out — the maltols at 9.24× baseline in gourmand formulas, furaneol at 13.25×. But that 13.25× rests on one formula. That is not a measurement; it is a coincidence amplified.

So only this sentence stays: the corpus cannot answer questions about the gourmand genre, because published formulas contain almost no gourmand perfumes. That may itself mean something (gourmand is a relatively recent commercial category and the corpus skews earlier), but that is a guess and I have no evidence for it.

For anyone building from a posted formula

• Check your dilutions are ready first. Twenty-two of this formula's 36 lines are dilutions. Without them you need a 200 g batch.
• Write the solvent into your formula. Your own formula should carry that TEC or DPG line too, or you will not know how strong the result is.
• Compute the smallest line once. Let it set your batch size, rather than deciding by feel.
• A 0.03 g scale cannot make this formula. Even fully pre-diluted it needs a 300 g batch.
• When a chemical name returns nothing, search the trade name too. Flavour materials are often filed under marketing names. I tripped over this myself in the first version of this piece.

What this doesn't establish

• I have not made this formula and have not smelled it. What is computed here is its composition, solvent share and required batch size, not whether it smells good.
• Dilution strengths were converted as she labelled them. A notation like "10 fois 10% DPG" I read literally as a 10% dilution; a different intent changes the numbers.
• I assumed the dilutions labelled 10% carry neat solvent. Some commercial pre-dilutions use other solvents, and the lines that give a strength without a base were handled as written.
• The batch calculation assumes ten scale divisions is acceptable precision. That is a common rule of thumb, not a standard. A stricter requirement means a larger batch.
• The two papers measured cooked beef and barley liquor, not crème brûlée. What I cite is the Maillard reaction volatiles they identified, and the Maillard reaction is the same reaction in all three. The step from "these are potent odorants in cooked beef" to "put these in a crème brûlée perfume" is one I have not taken.
• The three "no record / one supplier" lookups in this piece's first version were all wrong (corrected 28 August 2026). Sotolon has 41 suppliers, furaneol 101, maple lactone 72; the database files them as caramel furanone, strawberry furanone and cyclotene. The cause was searching the name column with chemical names.
• Twelve gourmand formulas is too few, so I ran no genre statistics. Every gourmand ratio I computed this round has been removed.