Should I mix perfume oils with alcohol or with a carrier oil?

April 19, 2019 8:41 AM

I have many BPAL (Black Phoenix Alchemy Lab) perfume oils that I don't wear enough because the bottles are inconvenient. I also have some cute empty clean rollerball bottles. If I wanted to dilute the perfume oil in the rollerball (because I don't want to decant the whole bottle for safety's sake as many are discontinued), should I use alcohol, or should I use a neutral carrier oil?

Bonus points: explain why.

posted by fiercecupcake to Clothing, Beauty, & Fashion (5 answers total)

This is something I have been interested in but don't have much first-hand experience yet. Here is one run-down I've read thgat suggests it's mostly a matter of preference, here is another that explains why they prefer oil.

The first sums it up like so:
Alcohol:
• Strong projection—the alcohol helps the fragrance molecules evaporate around you
• Makes certain ingredients sharper and more perceptible, so you can pick up on different notes at different times (top, middle, base, etc.)
• Overall effect is that of an evolving narrative—experiencing the notes individually, seeing how they change on your skin

Oil
• Subtle projection—the oil keeps the fragrance close to the skin, like a secret
• Softens the composition and mutes some of the top notes, so you get a more constant "scent" that's a little blurrier in terms of what goes in it
• Overall effect is that of a mood—experiencing the scent composition as a whole

This all matches well with my limited experience dabbling and my understanding of chemistry.
There are also cost considerations when buying new, but that won't apply for your case.

Additionally:
Ultimately, it's about how much you want the world to smell you. If you prefer something that has a strong sillage, a scent that trails behind you, go with a spray. And every time you check in on it, it'll smell like something slightly different.

But if you want something more intimate, or something subtle that won't trigger your coworkers' allergies, go for a perfume oil—what you'll get is a scent that's subtle but consistent.

On balance, I'll probably be sticking with oil for my experiments, though the experimental part of me will probably also try a mix of half carrier oil half alcohol, just to see what that's like. There's probably a good reason nobody does that, but hey maybe I'll like it :)
posted by SaltySalticid at 9:13 AM on April 19, 2019

I've had success in diluting mine with fractionated coconut oil as a carrier. My reason for doing that was partially like what you say- the bottles are inconvenient- but also because I have sensitive skin and the pure fragrance oil was occasionally making me react.
posted by rachaelfaith at 10:19 AM on April 19, 2019 [1 favorite]

Since the perfume oils are already mixed with oil, you should probably dilute with oil- the fractionated coconut oil rachaelfaith mentions is lighter than other oils and not so sticky.

If you mix the oil with alcohol, the mixture is likely to separate out (I've had this happen before when I've tried to mix an alcohol-based version and oil-based version of the same perfume)

The reason for this has to do with polarity and solubility: alcohol is a semi-polar, semi-nonpolar molecule. It's nonpolar/hydrophobic enough to dissolve scent molecules, but polar enough to mix completely with water. Generally carrier oils are going to be very nonpolar, too non polar to mix completely with alcohol. The carrier oil already in the perfume oil might be dissolving some waxier, very nonpolar components from the plants that make up the perfume, which definitely won't be soluble in alcohol and might make a waxy solid if you mix them.
(N.B. that a very short-chain, fractionated oil might be able to mix better with alcohol)
posted by zingiberene at 11:06 AM on April 19, 2019 [2 favorites]

Because of the problems with separation (even in oil) and possible rollerball leakage, I vote DIY solid perfume or scented lotion.
posted by Iris Gambol at 11:20 AM on April 19, 2019 [1 favorite]

This is answering your question a bit sideways, but I've turned a fair number of my neglected BPAL oils into sprays by putting them in small glass sprayer bottles, diluted with a water and alcohol blend. I usually do it like this (occasionally I go the hydrosol route but tbh most BPAL is complex enough as it is). Some I use for room/linen/clothing sprays, some I use on me, some I use to scent the air. Certain BPAL blends are cozy skin-scents for me, and those don't seem to work well as sprays, but experiment on your unloved imps!

I've tried rollerballs, but often find them a bit leaky and messy regardless of the carrier. My favourite Saje blends all come in rollerballs, and I'm always annoyed because it always leaks on my fingers (which can be quite painful when it's a minty blend, because then it inevitably gets in my eyes later!), and the last drops are always wasted. I also find that my skin eats up the carrier-oil-cut blends far too quickly, and I hate the constant reapplication.
posted by halation at 12:06 PM on April 19, 2019 [1 favorite]