What Is Methyl Undecyl Ketone?
Methyl Undecyl Ketone, also known by its chemical name 2-tridecanone, first appeared on the perfumer’s palette in the late 1940s when researchers isolated it during work on tomato leaf chemistry. Although tiny amounts exist in certain Solanum species, the quantities found in nature are far too small for commercial needs. Modern production therefore relies on laboratory synthesis, typically starting with renewable fatty alcohols that are upgraded through oxidation and selective chain-building steps. This approach gives a consistent, high-purity material that meets fragrance standards.
At room temperature the ingredient presents itself as a clear to faintly yellow liquid with a medium viscosity similar to light plant oil. It pours easily and blends without difficulty into most perfume bases as well as household product concentrates. Supply is steady thanks to simple raw materials and a straightforward process, so Methyl Undecyl Ketone is generally considered an affordable building block rather than an exotic luxury.
Usage is widespread yet often subtle. Many fine fragrances, personal care products and home care formulas include it in trace amounts to reinforce certain accords. Because it is stable in a wide pH range and shows good resistance to heat, formulators reach for it when they need a dependable material that will survive soap curing, detergent compounding or candle pouring without breaking down.
What Does Methyl Undecyl Ketone Smell Like?
Perfumers group this molecule in the herbal family. Off a scent strip it opens with a fatty green impression that quickly reveals an earthy, slightly waxy nuance reminiscent of crushed tomato leaf and moist soil. There is a mild dairy facet underneath that adds roundness rather than smelling overtly creamy, giving the overall profile a natural garden-fresh quality.
In traditional perfumery language we talk about top, middle and base notes to describe how an aroma unfolds over time. Methyl Undecyl Ketone behaves as a low-volatility middle note. It does not leap off the blotter like citrus materials yet it becomes noticeable within the first few minutes and anchors itself for many hours. Expect detectable presence well beyond the eight-hour mark under controlled conditions.
Projection sits in the moderate range. It will not dominate a blend unless overdosed yet it radiates enough to be felt by those standing at conversational distance. When dosed with restraint it threads through compositions, lending an earthy herbal backbone that stays close to the skin while supporting brighter or darker partners placed around it.
How & Where To Use Methyl Undecyl Ketone
Straight up, this is a pleasant material to handle: it pours smoothly, blends without fuss and does not have that eye-watering punch some green notes deliver neat. The muted color also means it will not stain bases or soap batter, a small but welcome bonus when you are juggling multiple trials.
Perfumers usually reach for Methyl Undecyl Ketone when they need to inject a natural, earthy greenness that feels more garden soil than fresh cut grass. It excels in tomato leaf, fig, basil, cannabis or tomato-stem accords, sitting between lighter leafy notes and heavier woody bases. Because it offers a fatty backdrop, it can also round out harsher terpenic materials, giving them a softer landing in the heart of the fragrance.
In fine fragrance a trace to 0.3 % is often enough to be noticed while staying discreet. Functional products tolerate a little more, with 0.5 % in shampoo or 1 % in detergent adding an outdoorsy freshness that survives wash off. If you push it toward 3 % you move from supporting actor to co-star and the waxy facet becomes more obvious. Above that point the note can feel oily and slightly dairy, so moderation is key unless that is exactly the effect you want.
It behaves well in most bases from alcohol to oil, survives cold-process soap curing and holds up in candle wax without heavy discoloration. One drawback is that its earthy signature can clash with overly sweet gourmand structures, so test carefully if you are building around vanilla or caramel.
No special prep work is required beyond the usual routine of weighing and prediluting. A 10 % solution in alcohol or dipropylene glycol gives a convenient dosing strength for both fine fragrance and household trials. The material is stable but cap the bottle tightly, as prolonged air exposure can dull the top green sparkle.
Safety Information
When working with any aroma chemical certain precautions and considerations are essential to maintain a safe lab environment.
- Always dilute before smelling: create a low-strength solution on a scent strip instead of sniffing the neat liquid
- Avoid direct bottle smelling: undiluted vapors can overwhelm your nose and mask subtler notes in the blend
- Provide good ventilation: use a fume hood or open window to prevent build-up of airborne chemicals
- Wear gloves and safety glasses: protect skin and eyes from accidental splashes during weighing and mixing
- Health considerations: some aroma chemicals may trigger irritation or allergic reactions; brief low-level exposure is generally safe but high concentrations or prolonged contact can be harmful; consult a doctor before handling if pregnant or breastfeeding
Always review the latest Material Safety Data Sheet supplied by your vendor and check it regularly for updates. Follow any IFRA guidelines that apply to ensure your usage levels remain within accepted limits and your finished product is both enjoyable and safe.
Storage And Disposal
If kept in optimal conditions an unopened bottle of Methyl Undecyl Ketone will usually remain fit for use for around two to three years. Once the seal is broken you can expect at least 18 months of reliable performance before the green facets begin to fade.
For storage the rule is simple: keep it cool, keep it dark, keep it tight. A shelf in a temperature stable room works, though refrigeration at 4-8 °C can squeeze out extra shelf life for large stocks. Direct sunlight and hot radiators accelerate oxidation so park the bottle well away from both.
Use screw-top bottles with a polycone insert for the best seal and reserve dropper bottles for short-term evaluation only. Topping off containers after each decant minimises headspace oxygen which is the main culprit behind aroma dulling. Always wipe the rim before recapping to avoid crusty residue that can compromise closure.
Label every container clearly with the material name, date received, dilution strength if any and a quick note on eye and skin irritation risk. Good lab habits prevent mystery liquids and keep everyone safe.
When it is time to discard leftover material small amounts may be flushed with plenty of running water if local regulations allow. Larger quantities should be mixed with an inert absorbent like cat litter then disposed of as chemical waste through an approved facility. Methyl Undecyl Ketone is readily biodegradable under aerobic conditions but concentrated dumps can still upset wastewater systems so moderation is key.
Summary
Methyl Undecyl Ketone is a lab-made re-creation of the earthy green note found in tomato leaves. On the strip it reads fatty herbaceous and faintly waxy sitting comfortably in the heart of a fragrance for eight plus hours. A whisper brings garden realism to fig basil cannabis or leafy florals while a heavier hand can push a soil-driven signature into the spotlight.
Stable in soap candles and detergents affordable compared with rarer green notes and easy to blend it has earned a loyal spot on many perfumers benches. Just watch dosage in gourmand builds and keep the bottle topped to fend off oxidation. If you need a versatile earthy herbal accent this is a fun ingredient to explore across an impressive range of accords.