How to run a proper burn test

  1. Trim the wick to 1/4 inch before every burn.
  2. Burn 1 hour per inch of container diameter (a 3″ jar = ~3 hours). This is the single most important rule.
  3. Check the melt pool. After the full burn time, wax should be melted edge to edge, about 1/4 to 1/2 inch deep.
  4. Note the flame. Steady, teardrop-shaped, 1–2 inches tall. Flickering, smoking, or dancing means trouble.
  5. Smell it. Check scent throw at the halfway point and near the end of the burn.
  6. Let it cool completely, then repeat for at least 3–4 full burn cycles before judging the candle.
  7. Write it all down — wax, wick, FO and %, pour temp, burn times, and what you observed. Future you will thank present you.

What’s wrong with your candle?

Tap a symptom to see likely causes and fixes.

These are the most common issues and fixes from real-world candlemaking. When in doubt, change one variable at a time and re-test.

How long should I burn a candle during a test?

One hour per inch of container diameter. A 3-inch jar needs about 3 hours per test burn to reach a full melt pool.

What causes candle tunneling and how do I fix it?

Tunneling is usually caused by a wick that’s too small or burns that are too short. Wick up one size and make sure every burn, especially the first, reaches a full edge-to-edge melt pool.

Why is my candle producing black soot?

Sooting is most often caused by a wick that’s too long or too large, or by drafts. Trim the wick to 1/4 inch before every burn and keep the candle away from vents and fans.