Why are the greatest scents in life so difficult to capture? I absolutely adore coffee, the mere scent is enough to awaken your senses and perk you up. Whether you like coffee or not, most people agree that it has the most wonderful smell, warm, toasty, nutty, bitter, dark and surprisingly complex. In fact, much of the enjoyment of drinking coffee comes from the aroma. Coffee in many shapes and forms is so easy to come by..but capturing its scent is much more elusive!
Much to my dismay many coffee fragrance oils just don't cut it -now I'm not throwing shade at all coffee fragrance oils completely. There are plenty of very pleasant coffee-like oils being manufactured in Australia but they often smell like a very sweet version of coffee with milk and other notes mixed in. Which is fine if that is what you are going for. But if you are after a true coffee bean roasted fresh-brewed aroma, bitter, dark and smoky then the fragrance oils on the market more often than not veer either towards caramel, chocolate, or buttery/nutty. And I have tried many coffee fragrance oils from suppliers both here and overseas.
So when it came to the coffee fragrance for my Melbourne candle I settled for the closest fragrance oil I could find to the real thing; however, I couldn't get the thought out of my head that I could do better. And when my wax had been discontinued by ecosoya and I was forced to re-formulate all of my candles I took it as an opportunity to do just that. I just had to pay greater homage to Melbourne - home to some of the best coffee in the world!
When you smell real roasted coffee beans and then you smell the fragrance oil - there's no comparison. Maybe there's a coffee bean note in there but it's being drowned out by other more overpowering fragrances in the mix.
So I started doing some research online - and you don't have to look far before stumbling across DIY coffee candle tutorials. One such idea is placing tealight candles in a bowl with coffee beans and when the outside of the tealights warm up they will warm the beans. While I haven't tried this technique I am sceptical as to how much scent throw you would get by the beans simply being in contact with a small amount of heat. I could be wrong, but even if I wasn't I wouldn't be able to apply that same principle to my own candles anyway. In essence, I am looking to fragrance the wax and not the area around the actual candle vessel.
The other DIY involved painstakingly sprinkling fresh coffee grounds between layers of wax. My first thought with this is that the granules could cause the wick to clog thereby effecting the burn of the candle and in the worst-case scenario might even cause a fire hazard. There is a trend at the moment of placing solid objects and trinkets into the top layers of candles (think crystals and herbs etc) While there are no current safety laws against this I would err on the side of caution and avoid putting anything with fine particles in the wax (but that is just my opinion) I think crystals and medium to largeish solid items would be fine in the wax if not flammable but I digress.
Another issue with this is that there are a lot of scientific reactions occurring in coffee beans and in the brewing process. The roasted bean smell occurs a few days after beans have been roasted during a process called degassing and to get that hit of aroma from ground coffee it would need to be brewed with water at quite a high temperature. When the wax is melting in a candle with grounds its not the same process as brewing pressurized grounds to make a coffee. You would be again just heating the grounds very slowly and at much lower temps resulting in little to no scent throw. I did do some experiments with grounds just to confirm these suspicions.
So having cancelled out both of those methods my next thought was making some sort of homemade coffee extraction. The problem being that I wouldn't be able to use water in the method as water and wax do not mix!
Experiment one: Create a coffee extract using vodka. Now vodka or perfumers oil can be a good choice when making a fragrance blend as alcohol is volatile, meaning that it will evaporate when burnt which is what you want when the candle burns to release the aroma chemicals in the air. So I sterilized the jar with boiling water and put my coffee beans in and let them sit in the vodka for a few weeks so the coffee oils could release their loveliness. I simply swooshed it around every now and then. What resulted was a very fragrant dark liquid which I then strained the beans out of thereby leaving the essence in the jar. Excitedly I blended this oil with my current coffee fragrance oil, which I used as a carrier in the wax and eagerly made a candle to see how it would go. Sadly all I could smell was the fragrance oil and the candle burned really badly, tunnelling and then the wick was engulfed with the wax.
Experiment two: Create an oil infused with coffee. I tried heating coffee beans slowly in vegetable oil in a slow cooker for many hours so the beans could release their oils that way, and then straining the beans out of the oil emulsion. I tried both the oil emulsion and the coffee extract in place of the fragrance oil in the candle (the oil being the carrier) and the same issue, no scent and a poorly burning candle. I re-wicked the candle, going one size up but again it was if the wax hated this amendment.
Experiment three: Coffee grounds simmered in oil for many hours, draining the grounds out of the oil wasn't enough to remove all of the particles and again the candle did not burn as expected.
Experiment four: Infusing the coffee beans and grounds directly into the wax using both slow cooker method and also heating the wax to a high temp. Same results.
Experiment five: I also tried reroasting the coffee beans in the oven first which in retrospect was a dumb idea as the beans themselves were pretty old and had already lost almost all their original aroma.
Experiment six: I tried different combinations of coffee fragrance oils with the above emulsions, I even tried a roasted coffee c02 oil adding it right at the end before pouring to avoid burning off the precious scent but still no Bueno.