candle making 101: smooth tops There’s nothing like the pristine surface of a smooth candle top! But this pleasing look can take some finesse to achieve in a finished product. If you’re struggling with rough candle tops, we’re here to help.

Three unlit candles with smooth tops are flanked by a glass thermometer and heat gun.

What are rough candle tops?

Rough candle tops are a cosmetic matter particularly common in soy wax candles. They usually look bumpy, lumpy, or pitted.

While rough tops don’t affect a candle’s performance, candle makers may find them aesthetically unappealing.

What causes rough candle tops?

Under ideal making conditions, your candle’s ingredients combine thoroughly and the wax is free of air bubbles. The candle cools at a steady rate and tiny crystals form in the wax as it solidifies. When conditions are just right, these chemical and environmental interactions result in a candle with a smooth top.

But we make candles in the real world where ‘ideal’ isn’t always possible. And the following factors can cause lumpy tops and rough surfaces.

Temperature shifts

If a candle cools too quickly, or there is a big difference between the temperatures of wax and the surrounding air, larger crystals may form in the wax and create a rough texture.

Air in the wax

Another cause of rough tops can be air trapped in the cooling wax. As the wax solidifies, air bubbles may rise to the candle’s surface. This can cause air holes and lead to texture in an otherwise great-looking soy candle.

Fragrance oil ingredients

Depending on your recipe, some fragrance oils may be more prone to rough tops than others.

Tips to attain smooth candle tops

There are two strategies to achieving smooth candle tops: repair and prevention.

While repairing rough candle tops adds a step to the candle making process, the good news is this fix is quick and effective.

Preventing rough candle tops can be trickier and your mileage may vary. Be sure to take detailed notes of the variables and your observations to figure out what works best for your process.

1. Repair rough candle tops with a heat gun

A few seconds of high heat from a heat gun will quickly melt the soy wax surface, level any bumps and make for a smooth candle top.
Don't have a heat gun? A hair dryer can work in a pinch. However, be aware the hair dryer's wider air stream may blow hot wax onto you or your work area.

2. Adjust the pour temperature

First, make note of the wax manufacturer’s recommended pour temperature.
Should rough tops occur at that temperature, try pouring 5-10°F warmer.
When lab notes are available for your wax, be sure to read them for more guidance.

3. Control the room temperature

Aim to make your candles in a temperature-controlled space between 68°F and 72°F.
A consistent ambient room temperature allows the candles to cool evenly.

4. Elevate the candles

Pour your candles on racks that are raised up from the work surface to encourage steady, even cooling.
No racks? Setting your candle vessels on corrugated cardboard can also work. The pockets in the cardboard allow air circulation under the candles.

5. Preheat your vessels

Warm containers to 90°-100°F before pouring.
This lessens the temperature difference between the wax and its surroundings and allows candles to cool more evenly.

6. Minimize the presence of air

Stir the wax gently when adding fragrance to minimize air bubbles.
By the same token, pour the wax slowly into the vessels to reduce possible air bubbles.

Smooth tops are in your future

Whether you prefer an ounce of prevention or enjoy using a heat gun, it’s completely possible to make a great looking soy candle. We hope these methods help you with your next batch of candles!

Have more candle making questions? Visit our Learning page for a host of help with our many resources, guides, and tutorials!