Stop the Sink: Your Essential Guide to Preventing Soy Wax Candles from Tunnelling

You light a beautiful soy candle, eager for its rich fragrance, only to find a deep, unsightly hole forming down the centre. This is “tunnelling,” a common but frustrating problem where unburnt wax walls cling to the side of the jar. Not only does tunnelling waste expensive wax and weaken the scent throw, but it also drastically shortens your candle’s lifespan.

As specialists in quality soy and natural waxes, Candlespro.com is here to tell you that tunnelling is completely preventable. The secret lies in understanding wax memory and applying three simple golden rules right from the start.

The Science Behind the Tunnel: Understanding Wax Memory

Soy wax, due to its low melting point and natural composition, is prone to developing wax memory. This memory is set during the very first burn.

When you light a candle, the heat creates a pool of melted wax. If you extinguish the flame before this pool reaches the edge of the container, the solidified wax forms a smaller circumference, setting the memory for all future burns. The wick will then only melt wax within this pre-set, smaller perimeter, leading to a sunken tunnel.

The Three Golden Rules for an Even Burn

To conquer tunnelling, you must commit to these steps for every candle:

1. The Critical First Burn Rule (The 3-4 Hour Commitment)

This is the most important rule. The first time you light your new soy candle, you must allow it to burn long enough for the melted wax pool to stretch all the way to the rim of the container.

• The Wait: For standard 8-oz to 16-oz jar candles, this typically takes 3 to 4 hours.
• The Goal: The entire top layer must become liquid. Do not blow out the candle until the melt pool touches every edge of the glass.

By doing this once, you effectively “train” the wax to melt evenly across the full diameter for the remainder of its life.

2. Wick Trimming: The Essential Pre-Burn Ritual

A longer wick creates a larger, hotter flame that burns the wax faster but often less efficiently, leading to soot and a potential tunnel.

• The Measurement: Before every single relighting, trim the wick to about 1/4 inch (6mm).
• The Tool: Use a dedicated wick trimmer (available at Candlespro.com). It catches the burnt debris and provides the clean, precise cut needed to control the flame size. A clean wick ensures a steady, controlled flame that melts the wax slowly and evenly.

 3. Location, Location, Location: Avoid the Draft

A common cause of lopsided burning (which quickly leads to tunnelling) is a breeze. Placing your candle near a window, air vent, or busy doorway will cause the flame to lean to one side.

• The Solution: Always place your candle on a flat, heat-safe surface away from drafts. This ensures the flame stands perfectly straight and melts the wax symmetrically.

Rescue Mission: How to Fix a Tunnelling Candle

Mistakes happen! If you discover a stubborn tunnel, you can often save your candle:

 The Foil Hug Technique

1. Wrap and Dome: Light your candle. Wrap a piece of aluminium foil around the rim of the jar, creating a small dome over the wax. Leave a small opening at the top for air circulation.
2. Harness the Heat: The foil traps the heat, essentially turning the candle into a miniature oven. This trapped heat will cause the stubborn, unburnt wax walls to melt down and join the central pool.
3. Level the Surface: Let it burn for 1–2 hours. Once the wax is completely level, remove the foil and extinguish the flame. Allow it to cool and solidify fully before lighting it again. The wax memory is now reset!

Conclusion: Enjoy the Full Life of Your Candle

Tunnelling doesn’t have to be the end of your favourite soy candle. By prioritising the critical first burn, committing to consistent wick trimming, and finding a safe, draft-free spot, you ensure a perfect, long-lasting, and fragrant experience right down to the last drop.

Ready to start burning smarter? Explore our collection of premium soy candles and essential candle care accessories today!