What Is Aldehyde C-18?
Aldehyde C-18 (so-called) is an aroma ingredient first isolated by chemists in 1908 during work on the sweet scent of ripe peaches. Today it is produced on an industrial scale by starting with plant-derived castor oil, converting it into a hydroxy acid then closing the ring to form a lactone. The technique is reliable and yields a material of more than 98 percent purity without the need for any added stabiliser. Although traces of this compound occur naturally in fruits, the version used in perfumery is fully synthetic which helps guarantee quality and keep supply steady.
At room temperature the ingredient is a clear liquid that can look colorless or faintly yellow depending on storage conditions. It pours easily, has a relatively high boiling point of 270 °C and a flash point above 100 °C making it simpler to handle than many lighter aldehydes. Because of its good stability and ready biodegradability it has become a staple in fragrance labs around the world. You will find it in countless fine fragrances as well as everyday products like soaps, shampoos and candles. Thanks to efficient production methods it sits in the middle of the cost scale so perfumers can use it generously without blowing the budget.
What Does Aldehyde C-18 Smell Like?
This ingredient falls into the fruity family. Off a blotter it opens with an immediately creamy coconut impression that quickly blends into a juicy white-peach tone. Within a few minutes a soft milky facet shows up, reminiscent of warm almond milk, while a gentle floral hint brings tuberose to mind without the indolic weight that pure tuberose absolute can have. The overall character is rounded and comforting rather than sharp.
In the traditional perfume pyramid Aldehyde C-18 sits squarely in the heart yet it bridges nicely into the drydown. It appears a few minutes after application, holds its presence through the middle phase then tapers off slowly over several hours. Projection is moderate: it creates a pleasing aura around the wearer without dominating a room. Longevity on skin is solid at six to eight hours, even longer in hair or on fabric, making it a dependable building block when a formula needs a smooth long-lasting fruity creaminess.
How & Where To Use Aldehyde C-18
This is a friendly material to work with. It pours without fuss, is not too volatile and does not stain glassware which already makes life easier in a busy lab.
Perfumers reach for Aldehyde C-18 when they need a creamy fruit note that feels more natural than synthetic peach bases yet softer than straight coconut lactones. It slips neatly into exotic fruit accords beside mango, pineapple or lychee. It also enriches white-flower bouquets by adding a milky flesh to tuberose, gardenia or ylang. In gourmand builds it bridges coconut, almond and vanilla giving the impression of coconut milk or peach custard.
The usual dose sits between traces and 5 percent of the concentrate. At 0.1 percent it only rounds the edges adding a subtle peach veil. Around 1 percent the coconut facet becomes clear and a buttery body shows up. Push it to 5 percent or higher and it dominates with thick creamy fruit that can feel heavy in delicate compositions so balance it with brighter lactones or citrus lifts.
Application wise it behaves well in fine fragrance, soaps, shampoos, candles and even strong detergents thanks to its good stability. One caution: in very high pH cleaning bases the sweetness can flatten so pair it with a leafy or green top note to keep lift.
Prep is simple. Pre-dilute to 10 percent in ethanol or DEP before weighing so you can dose accurately. No extra antioxidant is required since the molecule is already stable.
Safely Information
Working with any aroma chemical calls for sensible precautions and Aldehyde C-18 is no exception.
- Always dilute before evaluation: prepare a 10 percent solution in alcohol or dipropylene glycol before smelling
- No direct sniffing: avoid smelling straight from the bottle use a scent strip instead
- Ventilation: blend in a well ventilated space to prevent buildup of vapours
- Personal protective equipment: wear gloves and safety glasses to keep skin and eyes safe
- Health considerations: some individuals can develop irritation or allergies check with a medical professional if you are pregnant or breastfeeding and remember that prolonged or high exposure can be harmful even though brief low-level contact is generally considered safe
For complete peace of mind always consult the latest safety data sheet from your supplier and review it regularly since updates do occur. Follow all relevant IFRA guidelines to ensure your final formula meets current safety standards.
Storage And Disposal
When kept under the right conditions Aldehyde C-18 stays in spec for roughly three to four years. Quality slowly drifts after that but you will notice any change well before it becomes unusable.
The easiest way to maximise shelf life is to store the neat material in a cool dark cupboard away from heaters or direct sun. Refrigeration is not essential yet it does add an extra safety margin if you have space. Sudden temperature swings are what harm the material most so pick a spot and hold a steady climate.
Select bottles with tight polycone caps for both neat stock and dilutions. These liners form a better seal than dropper tops which let air creep in. Topping up the bottle whenever practical keeps the headspace small reducing oxidation and colour shift.
Label every container with the ingredient name concentration date filled and the relevant hazard pictograms. Clear records save headaches later and help anyone in your workspace handle the chemical responsibly.
Disposal is straightforward because the molecule is readily biodegradable. Small leftovers from skin or strip tests can go into normal wash water. Larger amounts should be mixed with an absorbent such as cat litter then placed in a sealed bag before disposal in accordance with local regulations. Never tip bulk liquid straight into drains as it can overwhelm treatment systems.
Summary
Aldehyde C-18 is a synthetic lactone that delivers a creamy coconut-peach aroma with a hint of tuberose. It works wonders in fruity florals gourmands and exotic blends bringing smooth milky body at very low dose and full-on tropical flesh at higher levels.
The ingredient wins fans for its stability friendly handling and fair price so it appears in everything from top shelf perfumes to everyday soap. Just remember to store it cool keep bottles tightly capped and dose with care or the rich fruitiness can steal the show.
If you enjoy experimenting this is a fun tool that slots into countless accords and rarely puts a foot wrong. Add it to your palette watch how it rounds harsh edges and discover why it holds a solid place on the aroma chemical hit list.