Sinkholes form around the wick after pour
Sinkholes are pockets of air formed when the outer skin of wax sets before the centre contracts. Common in soy and coconut blends when poured too hot or cooled too fast.
Why this happens
Wax shrinks as it solidifies. When the outer skin sets before the core has finished contracting, air fills the gap left behind. Hot pours, cold vessels, and drafty rooms all widen the temperature gradient that causes this.
Likely causes
- Pour temperature too high for the wax.
- Vessel was cold, causing the outer wax to skin instantly.
- Ambient temperature swing during cure (e.g. cold draft).
How to diagnose
- Cut a candle in half after full cure and inspect the cross-section.
- Note the pour temperature against the wax's manufacturer-recommended range.
Change sheet · next batch
Fill in what you know. The change sheet below re-orders so the delta most likely to help your specific batch floats to the top.
Slower cool means the core contracts before the skin sets.
Removes the hard temperature gradient at the wall.
80% main pour, 20% top-off once set covers most sinkholes.
Take action
- Rough or grainy tops after cure
Surface looks pitted, not glassy.
- Candle surface cracks after cure
Hairline or wide cracks across the top.