Guides / Candle history and craft
Curing and fragrance load
Why a freshly poured candle can smell weaker than one that has rested, how long different waxes need to cure, and what fragrance load means for scent, safety and burn quality.
What curing means
Curing is the resting time between pouring a candle and burning it. During this period, the wax finishes crystallizing and the fragrance oil becomes evenly bound within the wax structure. A properly cured candle usually has a stronger and more balanced scent when lit, especially its hot throw. See cold and hot throw.
A candle lit the day after pouring will still burn, but its scent may seem weak or uneven.
How long to cure
Cure times depend on the wax and fragrance. Common guidelines from candle makers and wax suppliers:
| Wax | Typical cure time | Notes |
|---|---|---|
| Soy wax | About 1 to 2 weeks | Many makers find scent keeps improving up to 2 weeks |
| Coconut and coconut blends | About 1 to 2 weeks | Similar to soy |
| Paraffin | A few days to 1 week | Often cures faster |
| Beeswax | Short; often a few days | Often used unscented |
Rich, heavy fragrances such as oud, amber and vanilla often benefit from the longer end of the range. See oud, amber and bakhoor.
Where to cure candles
- At room temperature, away from direct sunlight and heat.
- With lids on, or covered, so fragrance does not escape and dust stays out.
- Upright and undisturbed.
What fragrance load is
Fragrance load is the amount of fragrance oil in a candle, given as a percentage of the wax weight. For example, 1,000 grams of wax with 80 grams of fragrance oil has an 8 percent fragrance load.
Many container candles use somewhere around 6 to 10 percent, but every wax has a maximum it can hold, set by the supplier. Going above it does not make a candle stronger. It can cause:
- Sweating: oil beading on the surface.
- Soot and a large, unstable flame.
- A wick that drowns or struggles to stay lit.
- Safety concerns, because excess oil can affect how the candle burns.
Fragrance load versus scent strength
A strong scent depends on more than the amount of oil:
- The fragrance itself: some oils are naturally stronger than others.
- The wax: soy and coconut waxes are known for good throw; very hard waxes may hold fragrance more tightly.
- Adding temperature: fragrance is usually added at a specific temperature so it binds properly.
- The wick: a well-sized wick creates a full melt pool, which releases more scent.
- Curing: time lets the fragrance settle.
- The room: large rooms, open windows and drafts dilute scent.
Fragrance oils versus essential oils
| Fragrance oils | Essential oils | |
|---|---|---|
| Made from | Blends of aroma chemicals and natural materials | Plant extracts |
| Scent range | Huge, including scents nature cannot give, like "clean linen" | Limited to plant scents |
| Candle performance | Usually designed for candles, with good throw | Often weaker throw; some evaporate fast |
| Safety | Choose candle-safe oils with safety data | Natural does not mean safe for every use |
Tips for buyers
- If a new candle seems weak, let it rest a few more days with the lid on.
- Make the first burn long enough to form a full melt pool. See first burn and memory ring.
- Do not add essential oils to a store-bought candle; it can affect safety and burn quality.
Always follow the burn instructions on your candle's label. A candle overloaded with fragrance is not just weak or oily; it can burn with an unsafe, tall flame.
