Trimming the wick of a candle before lighting—even for the very first time—can noticeably improve your candle-burning experience. As Homesick Candles explains, a longer wick can create a larger flame and an uneven burn, which can interfere with how the wick absorbs the liquid wax and transforms it into a gas. This “incomplete combustion” can generate extra soot.
While some of the soot might end up on the jar (or your walls), it also has a tendency to collect on the wick itself. “Without trimming, you will get a ‘bloom’ on top of the wick which causes soot to fall back into the wax,” Cordelia Smith, founder of home products company Formula 55, told MarthaStewart.com. This can negatively affect the fragrance and "throw" (how a fragrance disperses) of your candle. According to the National Candle Association, diligent wick-trimming can also extend your candle’s lifespan by up to 25 percent.
How to Trim Candle Wicks
It’s generally agreed that the ideal wick length is roughly one-fourth inch. Lop off too much more than that and you may end up with a candle wick too short to light at all. If this happens, you can melt some of the wax with another heat source—e.g. a heat gun—and pour it out to uncover a bit more of the wick.
As for which wick-trimming tool works best, regular scissors will serve you well for a newer candle whose wick is still near the top of the jar. But the more the wax dwindles, the more difficult it’ll be to angle your scissors properly to make the cut. There are long, curved wick-trimming scissors on the market made specifically to avoid this issue: These sturdy CHEFBEE ones are $7 on Amazon. If you don’t burn candles often enough to warrant buying a special tool for the job, Insider recommends using your nail clippers.