Soy wax is one of those ingredients that sounds self-explanatory until you stop and wonder what it really is. The short version: it’s a vegetable wax made from soya beans. The beans are harvested, cleaned and rolled into flakes, the oil is extracted, and that oil goes through a process called hydrogenation, which turns it from a liquid at room temperature into a soft, creamy solid. That solid is the wax we pour.
Compare that to paraffin, which is the wax most mass-produced candles are made from. Paraffin is a by-product of refining crude oil. It works perfectly well as a candle wax, and it’s cheap, which is why it dominates the high street. The difference in origin is the whole story, though, because everything that makes soy behave the way it does comes back to the fact that it started life as a plant rather than a barrel of petroleum.
Soy Burns Slower
The first thing people notice with a good soy candle is the burn. Soy wax has a lower melting point than paraffin, so it burns at a cooler temperature. A cooler burn is a slower burn, which is why a soy candle of the same size will usually last noticeably longer than its paraffin equivalent.
A cooler burn also means less soot. Anyone who has watched a cheap candle leave a grey smudge up the side of the jar or along the wall knows the problem. Soot comes from incomplete combustion, and while no candle is completely soot-free, soy tends to produce considerably less of it than paraffin does. Keep the wick trimmed to about 5mm and you’ll cut that down even further (Denmead Candle wicks are self-trimming and you will rarely need to adjust them).
Soy + Essential Oils?
Scent matters enormously when the scent comes from essential oils rather than synthetic fragrance. Essential oils are delicate. Heat them too hard and the more fragile top notes simply burn off before they reach you. Because soy melts and burns at a lower temperature, it’s far gentler on those oils, releasing them gradually as the melt pool grows. That slow, even release is a big part of why soy and essential oils pair so well together.
Soy Can Cool With An Uneven Surface
On cooling, soy wax sets to a soft, opaque, slightly creamy surface. It’s worth knowing that soy is a little temperamental in this respect. You’ll sometimes see frosting, which is a white crystalline bloom on the surface or sides, or a slightly bumpy top after burning. Neither affects how the candle performs. They’re simply signs that you’re dealing with a natural wax that hasn’t had additives thrown in to force a flawless look.
On the practical side, soy is biodegradable and easily cleaned with water while it’s still warm, which makes reusing a finished jar refreshingly easy. When all the wax has melted and the candle is finished, wash the glass jar out with warm soapy water, and you’ve got a little glass vessel ready for a second life holding cotton buds, hair grips or a few wildflowers.
All Wax Types Leave A Footprint
Let’s be straight about the things soy isn’t, because every wax involves trade-offs. Soy farming has its own environmental footprint, particularly where land use and large-scale agriculture are concerned, so “plant-based” doesn’t automatically mean “no impact”. Other plant waxes (such as rapeseed) require intense pesticide use to grow. Whichever wax you choose, there are considerations for our planet.
It’s worth noting that a lot of candles labelled “soy” are actually soy blends, cut with a high percentage of paraffin or other waxes to make them easier and cheaper to work with, which is why reading the details matters.
Plant-Based Candles
On balance, we know our plant-based candles are made from a renewable crop, free of petroleum, that burns slowly and cleanly and treats its essential oils kindly. That’s the case for soy in a nutshell, and it’s why every candle we make starts with it.
If you’ve ever found yourself with a sooty jar or wall, or a candle that seemed to drain away far too fast, the wax was very likely part of the reason. Switching to soy won’t change your life, but it will quietly fix a handful of small annoyances you may not have realised you’d been putting up with.