What Makes A Candle Scent Last Longer?

This article will cover the key factors that determine how long a candle’s scent will last. We’ll look at how wick size, wax type, fragrance oil quality and concentration, candle additives, candle shape, candle curing, wick trimming, and other considerations affect scent throw and longevity. The goal is to provide a comprehensive overview of candle making techniques to extend fragrance life and create candles that smell great from the first light until the last.

Wick size

The thickness of a candle’s wick plays an important role in fragrance throw and longevity. Thicker wicks allow more melted wax and fragrance oil to travel up the wick. This enables more fragrance to be released into the air as the candle burns. Thicker wicks also tend to burn hotter, helping the candle reach an ideal temperature to melt and disperse the fragrance oil. Using too thin of a wick may result in poor fragrance throw as not enough melted wax reaches the flame. Selecting the proper wick thickness for the candle diameter and fragrance oil is key for maximizing fragrance strength and longevity.

Wax Type

The type of wax used in candle making plays a significant role in fragrance diffusion and how long the scent lasts. Natural waxes like soy, beeswax, and palm wax have a more porous structure compared to synthetic waxes like paraffin. The natural pore structure allows fragrance oils to diffuse more readily into the air. According to research, soy wax can hold up to 12% fragrance oil, while paraffin only holds around 8%. The increased porosity and surface area of natural waxes gives more area for fragrance to evaporate from the candle as it burns.

Synthetic paraffin wax has a much tighter molecular structure, with smaller pores that restrict fragrance diffusion. While paraffin candles can throw scent when first lit, the fragrance does not last as long compared to natural wax candles. Beeswax in particular has excellent porosity and ability to hold and release scent due to its honeycomb structure. In summary, opting for a natural wax with high porosity can extend how long your candle’s scent lingers.

Fragrance Oil Quality

The quality of the fragrance oil used in a candle can have a significant impact on how long the scent lasts. Higher quality fragrance oils contain molecules with better fixative properties that help the scent linger longer. Fixative molecules bind with the scent molecules and slow down the evaporation rate.

Synthetic fragrance oils made from cheaper ingredients tend to have poor fixatives, resulting in the scent fading more quickly as the candle burns. Higher end natural fragrance oils extracted from real plants and flowers contain more robust, long-lasting fixative molecules.

So when creating candles, invest in the highest quality fragrance oils you can. The better fixatives they contain will anchor the scent and allow it to evenly disperse into the air for a longer period of time as the candle burns.

Fragrance Oil Concentration

The concentration of fragrance oil, also known as fragrance load, is one of the most important factors determining how long a candle’s scent will last. Using the optimal percentage of fragrance oil for the type of wax and wick is crucial.

Most candlemakers recommend a fragrance load between 5-10% for soy wax candles. Going above 10% can cause issues like wet spots, collaboration, and smoking. For parasoy wax blends, 6-8% is ideal. Palm wax can hold more fragrance at 10-15%. Beeswax and coconut wax candles need higher loads from 15-18% due to their density.

No matter the wax, it’s essential to test different fragrance loads between 5-18% to find the sweet spot. The generally recommended starting point is 1 oz of fragrance oil per pound of wax. However, factors like wax thickness, fragrance strength, and wick size impact optimal percentages. Testing with sample candles identifies the highest fragrance load that burns cleanly without complications.

Higher fragrance loads often require larger wick diameters to avoid drowning the wick. Working with reputable suppliers provides guidance on usage rates. Finding the right balance of fragrance oil to wax type and wick size is key for maximum scent throw and longevity.

Sources:
https://www.scandinaviancandle.com/blogs/faq/how-much-fragrance-oil-to-use-in-your-candle

Candle additives

Certain additives can help anchor scent in candles and make it last longer. Two of the most commonly used are resins and polymers.

Resins are natural or synthetic substances that increase fragrance retention. They act like glue, sticking to fragrance oil molecules and preventing them from evaporating. Common resins used in candles include wood rosin, styrax, copal, and gum arabic. Adding just 5-10% resin to the wax blend can make a noticeable difference in fragrance strength and longevity.

Polymers like Vybar 103 are synthetic additives that boost fragrance retention. They increase the viscosity of the wax, making it harder for fragrance oil to escape. The higher molecular weight of polymers allows them to anchor scents. Using the right polymer at around 3-6% of the wax weight helps maximize fragrance throw and longevity.

Both resins and polymers work by binding to fragrance molecules. This anchors the scent and prevents quick evaporation from the wax. Candle makers can experiment with different additives and percentages to create the perfect scent throw and duration.

Candle shape

The shape of the candle can significantly impact how strong and long-lasting the fragrance is. This is due to the effect of shape on the surface area to volume ratio. According to Thompson Ferrier, irregularly shaped candles may burn unevenly and affect the overall burn time and fragrance throw. Candles with a higher surface area to volume ratio tend to have stronger fragrance, as there is more surface area exposed where fragrance can evaporate from. In contrast, candles with a lower surface area to volume ratio, like pillars or wide containers, have weaker fragrance. The shape impacts how quickly and evenly the wax pool forms when lit. An ideal shape for maximizing fragrance is a candle with straight sides and a flat top surface, which allows the entire top to melt evenly.

Candle Curing

Allowing candles to cure properly before burning is crucial for scent longevity. Curing refers to the process of allowing the candle wax to fully harden and stabilize after it has been poured and cooled. During this curing period, which can take 1-2 weeks, the fragrance oil molecules fully bind to the wax structure (Importance of Curing – Late Harvest Candle Co.). A properly cured candle will burn more slowly and evenly, allowing the fragrance to be released consistently. Burning a candle before it has cured can cause the wax to melt and pool unevenly, reducing fragrance throw. Patience is key – resist the urge to light that new candle right away. Allow it to cure first, and you’ll be rewarded with a better burn and lasting aroma.

Proper Wick Trimming

Properly trimming the wick is crucial for maximizing candle scent throw and longevity. As the candle burns, the wick will get longer and begin to bend and drown in the wax pool. This produces smoke and diminishes fragrance release. Trimming the wick prevents this.

Use candle wick trimming scissors to trim the wick to 1⁄4” before each burn. The optimal wick height is around 1⁄4”-1⁄2” to allow for proper capillary action of the melted wax while avoiding excessive black smoke (1). This helps the candle burn cleaner and release more fragrance.

Take care not to trim the wick too short, as this can prevent the wick from absorbing enough wax to sustain the flame. Aim for just the bare minimum of exposed wick to support the flame. Over-trimming will lead to the wick drowning faster.

Trimming the wick regularly to the ideal height is key for optimizing scent throw and longevity throughout the candle’s life (2).

(1) https://flame2scentcandles.com/blogs/flame2scent-candles-blog/the-art-of-candle-wick-trimming-a-guide-to-a-cleaner-safer-burn

(2) https://www.facebook.com/LeGra2u/

Conclusion

In summary, there are several factors that determine how long a candle’s scent will last:

• Larger wick sizes allow for more fragrance evaporation
• Paraffin wax helps fragrance throw better than vegetable waxes
• High quality fragrance oils last longer than synthetic fragrances
• Higher fragrance load percentages increase scent longevity
• Certain additives like UV inhibitors help stabilize fragrance
• Containers with more surface area expose more fragrance
• Allowing candles to cure fully allows for an even fragrance distribution
• Trimming wicks to 1⁄4” helps prevent soot issues

By carefully considering all these factors, candle makers can optimize their products for stronger, longer-lasting scents that delight consumers.