Fragrance Oil Blending: A Primer
Fragrance oil blending is perhaps the easiest way to distinguish your work from other candle lines. Not only is it a fun exercise in creativity, it allows you to produce unique aromas unlikely to exist anywhere else.
But where do you start? What are the rules? Surprisingly, and perhaps frustratingly, blending has no rules.
None.
Zip. Zilch. Nada.
Understanding basic science around fragrance and testing helps, but there aren’t hard and fast principles for developing new scents. Why? Because despite the incredible amount of concrete science (read: chemistry) required to develop fragrance, combining them is a beast untouched by rules.
Fragrance represents the intersection of art and science in the craft of candle making. Undoubtedly the most important consideration for customers is the scent promised in your candle – it’s here that our journey begins.
These aren’t rules, or principles, merely soft edges to your path of learning how to blend fragrances. Helpful categories for navigating an interesting and sometimes difficult aspect of the candle making trade.
Fragrance 101
Perhaps the only part of fragrance blending that makes any scientific sense is the notion of fragrance notes.
Every fragrance eventually evaporates into the air. The time it takes for it to fully evaporate makes it either a:
- Top note. Quick evaporation. High volatility.
- Middle note. Characteristic, memorable scent of the blend.
- Base note. Supports the top and middle notes and extends the longevity of the scent.
Fragrance is usually classified into one or two of these categories based on their volatility in the blend.
Like candles, fragrance operates as a system of notes. An ingredient or scent easily called a base note in one fragrance may be a middle note in another. Scents generally cooperate with other scents.
But, if you could extract a “single” note from a fragrance, you’d find they somewhat organize into certain families and note profiles. Here are a few examples of note generalizations. Many fluctuate between top/middle or middle/base depending on the source and the sister fragrances nearby.
| Top | Middle | Base |
| Orange | Rose | Vanilla |
| Lemon | Coconut | Cedar |
| Apple | Pineapple | Musk |
| Banana | Nutmeg | Amber |
Complex fragrances balance the contributions of each note layer as a compliment to your amygdala, which is subjective. Fragrance design comes down to balancing the top, middle, and base notes to accomplish a high performing, long lasting, pleasing aroma.
Creating A Masterpiece
Having a colorful fragrance wheel in front of you might tempt you to believe there are rules for combining, but there really aren’t.
You’ll potentially hear a lot of conflicting information about how to balance notes, but the truth is you can combine any amount of fragrance oils with any other amount in any ratio (base/middle/top) you want.
If you’re completely new to fragrance oil blending, consider starting with a “recipe”. Many candle making suppliers publish recipes online for things to try:
Many scents in these recipes are already blended to a degree. For example, Candles and Supplies suggests blending Blueberry Muffin with French Vanilla, so it’s okay to mix “pre-blended” fragrances into a blend.
Combining two fragrances with complex note profiles creates a unique fragrance with its own note profile. How do you validate these scents for candles? It comes down to testing.
Effectively Testing Blends
Fragrance oils (and essential oils) are the most expensive ingredient in a candle. Wild experimentation of fragrances that may or may not work can be a gamble, so for the sake of cost effectiveness consider growing the fragrance a few different ways before outright pouring a candle.
Rather than pouring your new gamble scent into a candle right away, take baby steps.
Use q-tips or cotton balls in a glass or plastic bag. While definitely the most juvenile way to test a scent outside of sniffing the caps at the same time, combining a little of everything you want together helps drive the “main idea” of the fragrance. Balance a few drops of whatever you want to combine onto a q-tip, cotton ball, or paper towel and place in a plastic bag or glass jar for three days. Time allows the fragrance notes to “get to know each other” kind of like a stew. If you still like it, proceed to the next stage.
Create wax melts or “salt tarts” to test throw in a slightly more formal structure. If you like what you smell in the blotters and q-tips, make something more candle-like to test it. If you don’t want to build complete wax melts, you can mix your fragrance oil blend with salt and put it on a wax melter/warmer.
Make a candle. After putting your new chemistry project through the non-testing gauntlet, make a complete candle with it. The only way to know if your blend will smell good, burn safely, and perform well is to make an actual candle. Wax melts and q-tips don’t necessarily represent the blend as it behaves in a candle!
Conclusion
Experimentation and bravery are the name of the game! Don’t be afraid to try new blends, especially if you have older oils approaching the end of their age. One way to squeeze more mileage from aging scents is to upcycle them into a brand new blended scent.
A word of caution, though – if you’re blending to find your next product line fragrance, make sure you source fragrance or essential oils you can easily re-stock if you need to. The last thing you want is to finally build a perfect blend only to find you can’t resupply the oils.
Additionally, take very good notes about how you’re balancing the amount of each oil in a blend to make sure your ratio is repeatable. Loyal customer’s are keen on what your product promises and they’ll easily pick up a change in your chemistry.
Above all – have fun with fragrance oil blending!
A Guide to IFRA Certificates for Candle Makers
What Are Flash Points, Anyways?
