Cody

Set a timer. Everyone's felt-two-minutes is about forty seconds.

Cold throw and hot throw are different problems. Judge a candle by lighting it after a fortnight, not by sniffing the jar. I have had jars that smelled of nothing cold and filled a room burning.

Pretty much. Burn one jar at day 14 and judge the batch on that.

Exactly. It looks perfect for an hour and then tells the truth.

You are treating the symptom. A sinkhole is the surface setting while the core is still liquid - the skin forms, the middle shrinks underneath it, and it pulls down around the wick because that is the hottest column.

Slow the whole cool down. Pour at 54 to 57C into warmed jars, cover with a box, do not move them for four hours. If you still need a top pour, do it while the surface is still soft rather than after it has fully set, with wax about 5 to 8 degrees above your pour temperature. A cold top pour onto a set candle is exactly what gives you the dip a day later, because the two layers shrink independently.

Go up, but test properly, and fix the flame separately because it is a different signal.

A CD10 in a 7cm jar at 8 percent fragrance is under-wicked. Fragrance oil raises the effective melt point and a heavily scented soy needs more heat than the wick chart implies - the charts assume unscented wax and nobody makes unscented candles. I would burn CD12 and CD14 side by side rather than stepping up one at a time.

The 2cm flickering flame is separate. Tall and dancing usually means the wick is too long, not too big. Trim to 5mm before every burn including the first. A long wick burns tall, sooty and hot at the top while still not throwing heat outward, which is precisely the picture you have.

One more thing: three and a half hours should have reached the glass. Once a memory ring is set that jar will tunnel forever. Do your testing on fresh pours, not on that one.

Five millimetres every single burn, and let burn one go the full distance to the glass. Those two habits fix more candles than wick changes do.

A box over the batch is easy enough. Do you preheat with a heat gun or the oven?

Worth adding that the blend also needs a different wick size, so it is not a drop-in swap mid-season.

Blend, if strangers are paying money for them. Straight soy at 8 percent in a room that swings four degrees will give you frosting, wet spots and uneven tops, and you will spend more time fixing surfaces than making candles.

At gift scale for yourself, straight soy is fine and the price difference is real. The line for me is whether somebody is buying the look.