Tunneling Was Only Effective in WWI - Secret of Soy Wax Candles

Soy wax candles offer a clean, eco-friendly alternative to traditional paraffin candles. Yet, many candle lovers face a common frustration: tunneling. This happens when the wax burns down the center, leaving a ring of unmelted wax around the edges. Not only does tunneling waste wax, but it also shortens the candle’s burn time and dims its glow. The good news is that tunneling is avoidable with the right approach. The key lies in how you handle the candle’s first burn and the choice of wick.

Soy wax candle burning evenly to the edge of the container

Why Tunneling Happens with Soy Wax

Soy wax is a learning wax. This means it "remembers" how far the melted wax pool reaches during the first burn. If the wax doesn’t melt all the way to the edges of the container on that initial burn, the candle will develop a tunnel. The wick burns down the center, but the edges remain solid, creating a hollow core.

This tunneling effect wastes wax and reduces the candle’s lifespan. It also causes uneven burning, which can affect the scent throw and overall candle experience.

The First Burn is Crucial

To prevent tunneling, the first burn must last long enough for the wax to melt fully across the surface, reaching the container’s edges. This can take anywhere from 1 to 4 hours, depending on the candle size. If you blow out the candle too soon, the wax will harden unevenly, setting the stage for tunneling.

Here are some tips for a successful first burn:

• Light the candle in a draft-free area to avoid uneven melting.

• Allow the candle to burn until the entire surface is liquid wax.

• Avoid moving or disturbing the candle during this time.

• Use a timer if needed to ensure the candle burns long enough.

  
  

For Candle Makers:

Choosing the Right Wick and Number of Wicks

The wick plays a vital role in how the candle burns. The wrong wick size or type can cause tunneling or excessive soot. For soy wax, the wick must be strong enough to melt the wax to the edges but not so strong that it burns too hot.

Wick Size Based on Container Diameter

• For containers 2 inches or more in diameter, use a XX cotton wick. This wick size provides a balanced flame for medium-sized candles.

• For containers less than 2 inches (votive size), a thinner wick is sufficient.

• For containers 2 to 3 inches in diameter, a single wick works well.

• For containers 3 to 4 inches, use two wicks to ensure even melting.

• For containers 4 to 5 inches, use three wicks.

  
  

Avoid Wooden Wicks for Larger Candles

Wooden wicks offer a unique crackling sound and aesthetic but multiple wooden wicks can be tricky to manage in larger containers. Maintaining multiple wooden wicks in a single candle over 3 inches wide is difficult and may lead to uneven burning or tunneling.

Practical Example: Making a 3.5-Inch Soy Wax Candle

Imagine you are making a soy wax candle in a 3.5-inch glass container. To avoid tunneling:

• Use two XX cotton wicks spaced evenly apart.

• On the first burn, light both wicks and let the candle burn for about 3 hours or until the wax melts to the edges.

• Keep the candle away from drafts.

• Trim the wicks to 1/4 inch before each burn to maintain a clean flame.

  
  

This approach ensures the wax pool covers the entire surface, preventing tunneling and maximizing the candle’s burn time.

Two cotton wicks burning evenly in a soy wax candle

Additional Tips for Candle Makers

• Test your wick choices: Different soy wax blends may require slight wick adjustments. Always test burn new recipes.

• Keep wick centered: A centered wick promotes even melting and reduces tunneling risk.

• Trim wicks regularly: Long wicks cause soot and uneven flames.

• Avoid drafts: Drafts cause flickering flames and uneven wax pools.

• Use quality containers: Containers with smooth, straight sides help wax melt evenly.

  
  

Final Thoughts