Soy vs. Paraffin: What's Actually in Your Candle
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Most people never think about what their candle is made of. It smells good, it looks nice, it burns. But wax is the largest ingredient in a candle, and soy and paraffin come from very different raw materials.
That difference matters — just not in some of the exaggerated ways candle marketing sometimes suggests. Wax is only one part of a candle. Wick size, fragrance load, vessel shape, airflow, and how the candle is burned all affect performance too.
Where soy and paraffin wax come from
Paraffin is a petroleum-derived wax produced during crude-oil refining. Soy wax is made from soybean oil that is processed into a solid wax suitable for candlemaking.
Both are widely used candle fuels, and both can be formulated in different ways. That means two candles labeled “soy” can perform differently from each other, just as two paraffin candles can.
Does soy automatically burn longer?
You’ll often see claims that soy candles last a specific percentage longer than paraffin candles. We don’t think that is a useful promise. Burn time depends on the entire candle design — including the wax formulation, wick, vessel diameter, fragrance load, and burn conditions.
Different soy and paraffin formulations also have different melting ranges. A lower melting point can affect how a candle forms its melt pool, but the wax label alone doesn’t tell you exactly how many hours a candle will burn.
The most useful comparison is the tested burn time of the specific candle you’re buying, not a blanket claim about one wax family.
What about soot and indoor air?
Any burning candle is a small combustion source, so no candle wax is literally soot-free. Research on candle emissions shows that wax composition matters, but so do fragrance, wick design, flame stability, drafts, and other burn conditions.
That’s why we don’t describe paraffin as “toxic” or soy as “non-toxic.” The evidence is more nuanced than that. Studies comparing candle emissions have found meaningful differences among individual candle formulations rather than one simple rule that applies to every soy or paraffin candle.
Good candle care matters regardless of wax type: keep the wick trimmed to about ¼ inch, keep the candle away from drafts, and stop burning if the flame becomes unusually large or the candle begins visibly smoking.
The wick matters too
Lead-cored candlewicks were banned from manufacture and sale in the United States in 2003. Back Porch candles use lead-free cotton wicks.
Wick size is matched to the wax, fragrance, and vessel because it controls the flame and melt pool. A wick that is too long or a flame disturbed by drafts can increase visible soot, which is another reason regular trimming matters.
Where soy behaves differently
Soy wax has a few quirks that are worth knowing about. It can develop “frosting,” a pale crystalline appearance on the surface or sides of a candle. That is a normal cosmetic change in vegetable-based wax and doesn’t mean the candle has gone bad.
Soy wax can also be sensitive to temperature swings, so a candle left in a very hot car or direct summer sun may soften or change texture. Those appearance changes are part of working with this material rather than signs of poor quality.
Why Back Porch chooses 100% soy wax
We use 100% soy wax because it fits the candles we want to make: hand-poured in small batches, with a smooth melt pool, dependable fragrance performance, and a material we’ve worked with for years.
It’s a formulation choice we’re proud of — not a claim that one wax alone determines whether a candle is “safe” or “clean.” Every Back Porch candle is made in Loveland, Colorado with 100% soy wax, a lead-free cotton wick, and premium fragrance oils.
Sources and further reading
- U.S. Consumer Product Safety Commission: Candle Business Guidance
- National Academies / NCBI: Sources and Composition of Indoor Particulate Matter
Browse the Farmhouse Collection, learn more about why we choose soy wax, or read our candle care guide for practical tips on getting the best burn from your candle.