If you’ve ever poured a beautiful candle only to find cracks forming as it cools — you’re not alone! Wax cracking is one of the most common issues candle makers face. The good news? It’s also one of the easiest to fix once you understand why it happens.
What Causes Wax Cracking?
Cracks in candles usually appear during the cooling or setting stage, and they can happen for a few key reasons:
Temperature Shock
If the wax cools too quickly, it can contract unevenly, leading to cracks on the surface or along the sides of the jar.
Common culprit: pouring your candles in a cold room or placing them near a draft.
Overheating or Underheating the Wax
Pouring wax that’s too hot or too cool can both cause issues. Overheated wax may shrink as it sets, while wax that’s too cool can start solidifying before it’s properly poured.
Rapid Cooling of the Container
If your jars or tins are too cold, they can shock the wax as it’s poured, creating surface cracks or sinkholes.
Wax Type
Some waxes (like soy) are more prone to cracking due to their natural properties and how they contract as they cool.
How to Prevent Wax Cracking
1. Control Your Room Temperature
Work in a warm, stable environment, ideally between 18 °C and 25°C. Avoid cold surfaces, fans, or drafts that speed up cooling
2. Pre-Warm Your Containers
Pop your jars or tins in a warm oven (around 50°C) for a few minutes before pouring. This helps the wax and container cool at the same rate.
3. Pour at the Right Temperature
Always follow your wax manufacturer’s recommendations, but in general:
- Soy Wax: 55–65°C
- Paraffin Wax: 70–80°C
- Coconut Blends: 60–70°C
4. Cool Candles Slowly
Let your candles cool at room temperature. Don’t place them in the fridge or near open windows.
5. Stir Gently and Consistently
Avoid whipping air into your wax — this can lead to surface imperfections and weak spots that crack later.
How to Fix Cracks in Finished Candles
If you already have cracks — don’t panic! You can often fix them with one of these quick tricks:
- Use a heat gun: Gently re-melt the top layer of the candle to smooth out surface cracks.
- Double-pour method: Pour a small amount of leftover wax on top to fill in the cracks and level the surface.
Wax cracking might look like a big problem, but it’s usually just a small tweak away from perfection. Keep notes on your pouring temperatures, room conditions, and cooling times — this helps you pinpoint what works best for your setup.
Remember: every candle maker experiences hiccups at first. The key is learning, adjusting, and enjoying the creative process along the way.