How Does Vanillin Affect Candles?

Published by Kevin Fischer on

Fragrance oils allow us to create candles that emulate almost anything in nature through the power of scent. The market contains a large variety: everything from the ever-popular Lavender to more obscure and oddly specific beer flavors.

Although this great selection lends incredible variety in terms of candles out there, crafting oils with the right properties requires a visit from the friendly fragrance.

Vanilla. Or more specifically, vanillin.

Vanilla is a friendly fragrance used to develop a lot of different not-vanilla fragrance oils. It blends well with lots of different actors to accentuate the sweeter parts of other scents.

But this all-purpose ingredient comes at a cost to candle makers; vanilla often causes discoloration leaving a brownish hue on an otherwise white or off-white base. Why does this happen? What can we do about it?

We’ll talk about it, but first a small divergence into the vanilla market to set up some context for it’s role in candle making.

Vanillin vs Vanilla

Vanillin and vanilla are different, and the easiest way to understand both is to start with explaining the origin of vanilla.

Put bluntly, the world consumes more “vanilla” than we can produce. Many foods and other products use vanilla in as an ingredient, but the raw commodity is relatively scarce!

It only grows within 10° to 20° latitude of the earths equator or in a greenhouse. Madagascar. Tahiti. Mexico. Not a huge deal in and of itself, but the process to extract vanilla spice from the vanilla pod requires an intense labor process.

According to Scientific American, 1 kg of cured beans (the good stuff) requires 600 hand-pollinated blossoms. Every bean goes through rigorous inspection over a decent period of time meaning farms don’t have the luxury of tremendous output.

Pure vanilla bean production is a careful, limited process.

To make up the difference, smart people determined we can “fake it”. Turns out, a lot of the parts of vanilla we enjoy and use actually come from one of it’s many compounds, vanillin.

Where vanilla is a spice with many different compounds, vanillin is a single organic compound that evidently makes up 80% of vanilla’s flavor. It’s just as desirable as a substitute because most people won’t even notice the difference!

You might be thinking, “Okay, but if vanilla is somewhat scarce, wouldn’t vanillin be too?”

Naturally occurring vanillin is also scarce, yes, but scientists have found a way to synthesize vanillin in a laboratory for a much lower cost than vanilla.

Next time you’re reading through ingredients, vanillin isn’t a typo. Vanillin is the cost-effective market substitute for vanilla and it works really well! Candle makers have probably noticed that some fragrance oil suppliers specifically mention the vanillin content on their products – let’s talk about that.

Vanillin in Fragrance Oil

You might wonder why vanillin is listed on tons of non-vanilla fragrance oils. The answer lies in the chemistry of fragrance oil development.

Remember how fragrance oils contain a lot of trade secrets and therefore don’t usually disclose their ingredient list? Turns out vanillin is commonly used in fragrance development for two major reasons.

As A Fixative

Fragrance development is largely finding great ingredient combinations for scent and then extending their life. All scents are composed of top, middle, and base notes.

Top notes come from compounds with lower boiling points – they hit you hard and fast before disappearing quickly from a scent. Base notes last the longest and support the bulk of a fragrance’s life. Sometimes perfumers need just an extra oomph to extend the fullness of a fragrance and hold on to the higher notes for just a little longer.

Fixatives play this role extremely well.

Fragrance with ingredients all over the map might be inconsistent or fleeting without a fixative. The fixative makes the entire fragrance last longer by anchoring volatile notes to the scent so they don’t evaporate as quickly.

They come in many forms, but vanillin serves as a relatively popular fixative in many fragrance oils. Not only for it’s chemical interactions with other notes, but because it seamlessly adds a warm, sweet tone to the entire blend.

When enough vanillin is used, it may even serve as the base note of a fragrance, but it doesn’t always have to take center stage in a smell. It’s presence helps reduce overall volatility in other ingredients, but that’s not the only reason developers include it.

For It's Reputation

Do you know someone that brings the best out of you? A friend that everyone likes being around because she doesn’t make a fuss out of herself and encourages and enriches the group instead?

Your friend might be vanilla, but not in the bad, generic way. Vanilla/vanillin plays well with other fragrances. Known for being a fixative, it rounds out a fragrance well and adds a lot of volume to a mix without overpowering.

Scroll through a supplier’s list of fragrance oils and you’ll see a lot of vanilla-themed scents. It’s easy to mix and it compliments more than it combats.

Discoloration in Candles

Not everyone discloses their ingredient list, but more reputable suppliers will tell you the vanillin content (if there is any) because it’s known to impact candle design.

The ugly side of vanillin in wax and soap design is it’s propensity for oxidation. Exposure to UV (sunlight) and oxygen often transforms its color to a beige or brownish hue.

Not too pretty when you want a different color, right?

Some candle makers rely on this as a feature of their candle, purposefully leaving out any dye to allow the transformation of color to characterize their creation. Unfortunately, the uncontrollable side effects aren’t for everyone, so what can you do?

Well, the good news is that discoloration is merely cosmetic – it does not affect the candle’s performance.

If you’re making soap (this isn’t a soap making website) there are products intended to combat discoloration, like Vanilla Stabilizer. Do not use this for candles. It isn’t oil soluble.

Your best options for candle making are either preventative or cheekiness.

Preventative care is removing or reducing the overall vanillin content in your fragrance blend. You can also store and display the candle with great care: keep the container covered (if a container candle) and store out of direct light. Obviously this strategy goes out the door once the customer takes it home, but they probably don’t care as much as you do!

Cheekiness involves hiding the problem. If you’re making container candles, you can use dark colored walls or tins to hide imperfections (this strategy works great against frosting too). You can also use a dye that “balances” with the beige/brown color. While slightly unpredictable, some colors will make the discolored brown look like a feature or hide it altogether when done well.

Conclusion

Vanilla and vanillin are powerful ingredients in fragrance design. Some of the most popular oils used today are based on vanilla or use it to accentuate and extend the other notes.

Unfortunately, the natural vanilla market is overwhelmed by demand. If you’re concerned about integrating natural ingredients in your line, you may want to research synthetic vanillin to see if you’re okay with it.

Synthetic vanillin is considered very safe by many industries, but your incorporation of it depends on your principles and requirements.

Discoloration is somewhat unpredictable. Some candle makers build formulations with higher vanillin content and never deal with severe problems. Others barely think about vanilla and their candles immediately discolor. Your mileage may vary!