Do I Need to Cure my Candle?

Should a candle be left to cure for two days, or rather two to three weeks? Does it even matter?

This is one of the questions candle makers ask most often. Let’s take a closer look at why a candle’s curing time might be important.

Many people think that a candle is ready to burn as soon as the wax has hardened. In reality, slow processes take place in the wax after it hardens—processes that are invisible to the naked eye. These continue for some time after the candle is made.

The curing time depends on the type of wax

There are different types of wax available on the market:

• paraffin waxes;
• vegetable waxes;
• various blends of these.

Paraffin wax

For candles made from paraffin or paraffin blends, 2–3 days is usually sufficient.

Paraffin is a relatively stable material and quickly becomes suitable for burning after hardening. Fragrance diffusion is also usually good after just a few days, as paraffin’s molecular structure quickly binds the fragrance oil and rapidly settles into its final form.

Therefore, paraffin candles can be tested for both wick suitability and burn time after just a couple of days.

Plant-Based Waxes

Soy, coconut, and other plant-based waxes behave differently.

Their molecular structure is polymorphic—the wax consists of many small crystals that become progressively stronger and more stable over time.

When melted, the crystals expand, and when they solidify, they contract again.

If the crystals do not solidify completely evenly, a so-called frosting—a crystalline pattern resembling frost—may form on the candle’s surface.

In cooler environments, the edges of the candle may contract faster than the center. As a result, so-called wet spots may form on the sides of the container, where it appears as though the wax has separated from the glass.

The harder the wax, the more likely this phenomenon is to occur.

Why does the scent get stronger?

As the candle cures, the fragrance oil molecules distribute more evenly throughout the wax.

If you light the candle just 2–3 days after making it, the scent may seem weak because the fragrance oil hasn’t fully bonded with the wax yet.

After about two weeks:

• the wax has hardened;
• the crystal structure has stabilized;
• the fragrance oil is better incorporated into the wax;
• the scent diffusion is noticeably better even before lighting the candle.
• The candle also typically burns more evenly and for a longer period of time.

Therefore, we recommend testing candles made from plant-based waxes only 2–3 weeks after production.

Curing also affects the wick

The suitability of the wick should not be assessed immediately after the candle is made.

If you test the wick after about 24 hours, it may seem too long.

After 2–3 weeks of curing, the same wick may prove to be perfectly suitable, as the candle will then burn more evenly, cleaner, and slower.

When should a candle be put up for sale?

The manufacturer never knows when a customer will light the candle for the first time. This could happen in a few weeks, several months, or even half a year.

To ensure the customer gets the best possible experience from the candle, we recommend not selling candles made from plant-based waxes until at least two weeks have passed since their production.

This way, the candle:

• has a stronger scent;
• the burn is more stable;
• the burn time is longer;
• the overall quality is better.

Recommendation for Manufacturers

Test candles made from plant-based waxes only after at least 2–3 weeks of curing, and develop your recipes based specifically on these results.

We also recommend:

• record the production date of each batch;
• set a recommended sell-by date for the batch;
• store the candles for at least 2–3 weeks before selling them.

This will help you avoid a situation where a customer lights the candle too soon and is disappointed by its scent diffusion or burning characteristics.