What soy wax is, and how it behaves in a candle

Soy container wax is soybean oil that has been hydrogenated until it is solid at room temperature, usually blended with other soy-based ingredients so it pours smoothly, holds fragrance and clings to glass. Because it is a vegetable fat rather than a petroleum wax, it crystallizes the way fats do, which is why soy candles can frost, pull away from the jar and need a short cure before they smell their best. This page explains what a soy container wax is made of, using a patent and two named data sheets, how it behaves from pour to burn, and what "100% soy" can and cannot mean on a label.

What is in a bag of soy container wax

The clearest public description of soy container wax comes from patents rather than marketing. U.S. Patent 6,797,020, Triacylglycerol based wax for use in container candles, issued September 28, 2004 to inventor Timothy A. Murphy [1] [9], describes a triacylglycerol-based wax (a triacylglycerol is the fat molecule in vegetable oil) for container candles with these properties [1]:

• Melting point "generally about 50 to 55" °C (122 to 131°F) when the wax is used in a container candle, within a broader range of about 49 to 58°C.
• Iodine value of about 45 to 65, desirably about 50 to 60. Iodine value is a measure of how many double bonds remain in the fat; a lower number means a more fully hydrogenated, harder fat.
• How it is made: by blending fully hydrogenated vegetable oil (hydrogenated to an iodine value of no more than about 5) with partially hydrogenated oil to reach the target.
• Paraffin: the candles are "preferably substantially devoid of paraffin," and the claims allow "no more than about 1.0 wt. % paraffin."
• Additives: colorants at about 0.001 to 2 percent of the wax, and 0.1 to 5.0 percent of a migration inhibitor, an ingredient that keeps fragrance and dye from creeping to the surface.
• Behavior it is designed for: to "promote surface adhesion to prevent the candle from pulling away from the container" and to avoid "undesirable mottling ... which results from uneven wax crystallization."

Related patents by the same inventor, both assigned to Cargill, describe a harder soy wax for pillars and votives with a melting point of about 60 to 66°C and an iodine value of 10 to 20 (US 6,773,469, granted August 10, 2004) [2], and an earlier version for votives, pillars and tapers at about 54 to 63°C (US 6,503,285, granted January 7, 2003) [3]. The difference between the container and pillar versions is the whole story of soy wax in one comparison: the more fully hydrogenated the oil, the harder and higher melting the wax.

The assignee of 6,797,020 itself was not confirmed from a front page, so this page names Cargill only for the two patents where Google Patents shows it. The patents describe a category of wax. They do not tell you what is in any product on sale. For that you read the seller's data sheet.

Two soy waxes, two data sheets

Here is how two soy container waxes are described by the companies that sell them. Each figure is that seller's figure for that product.

CandleScience's own beginner tutorial adds fragrance to SimplySoy at 185°F, five degrees higher than the product page [6]. Both figures come from the same supplier; how to make a soy candle follows the tutorial and names both. The bigger point is in the table: two products sold as soy container wax differ by about 9°F in melt point, 25°F in pour temperature and a percentage point in fragrance limit. Use your wax's own sheet. Reading one line by line is covered on buying wax and reading a data sheet.

How soy wax behaves, pour to burn

It shrinks and can pull away from the glass

All waxes contract as they cool. Soy wax tends to show it as patches where the wax has separated from the glass, which makers call wet spots because they look damp. The GW 464 instructions say slower cooling encourages adhesion to the container and faster cooling encourages pull-away, and they ask for an ambient 70°F with jars about 1/2 inch apart [4]. Wet spots are cosmetic; causes and fixes are on the wet spots page.

It can frost

Frosting is a white, crystalline bloom on the surface or against the glass of a vegetable wax candle. It is a crystallization effect in the fat (the patent above describes mottling that "results from uneven wax crystallization" [1]), and temperature during and after cooling plays a part. The GW 464 instructions say cooling too fast or too slow can cause concaving or frosting [4]. Suppliers market their soy waxes on frost resistance, as both sheets above do, and blends are often formulated partly to reduce it: CandleScience saw no frosting in its coconut apricot test candles [7]. Frosting does not affect the burn. The crystal science and what reduces it are on the frosting page.

Its throw develops over a cure

Fragrance needs time to settle into a vegetable wax before the candle smells its best, and each supplier gives its own minimum: 48 hours before test burning GW 464 [4], at least two days for SimplySoy [5]. Those are minimums from two sellers for two products, and neither is a rule for soy. No published source was found for the much longer cure often quoted for soy in general. How to set your own cure by testing is on how long candles need to cure.

It is relatively viscous when melted

Melted soy wax is thicker than some blends, which changes how much fuel the wick can draw. CandleScience found its coconut apricot blend less viscous than pure soy, so it travels through the wick faster and "will generally need a smaller wick than soy wax" [7]. The practical reading is the reverse: soy tends to need a larger wick than a lower-viscosity blend in the same jar. Start from a wick chart column made for soy, then test, as described on how to size a wick.

It has a low melt point

A container soy wax that melts around 113 to 128°F can soften in a hot car, a parked delivery truck or a sunny window. SimplySoy's page markets its higher melt point for shipping in high temperatures and outdoor markets [5]; GW 464's sheet asks for storage away from direct heat and sunlight because of its low melt point [4]. Testing a candle for heat is on the melt point page.

What "100% soy" can and cannot mean

Three different things get called "100% soy," and they are not the same claim.

1. The wax is entirely soy-derived. SimplySoy is listed with soy as its only ingredient, including its "soy-based performance additives" [5]. That is a statement about the wax you can document from the supplier's page.
2. The wax contains a small amount of something else. The container wax patent above allows up to about 1.0 percent paraffin in its claims [1]. A product made that way is mostly soy, but the patent alone does not tell you whether any particular wax contains paraffin. Ask the supplier, in writing.
3. The candle is 100 percent soy. A finished candle also contains fragrance oil (SimplySoy's container limit is 10 percent of the wax weight [5]), dye and a wick. The wax can be all soy while the candle is not.

If you want to print "soy wax" or "100% soy wax," keep the supplier's written statement of composition with your batch records, and print what that statement supports. What the FTC's rules say about such claims is on what you can claim about your candle.

Soy wax and clean-burning claims

Soy is often sold as cleaner burning or healthier than paraffin. The 2009 university study most often cited for that was never published in a peer-reviewed journal, according to a supplier that looked into it [8], and no good peer-reviewed comparison of soy and paraffin emissions has been published. What the research does and does not show is set out on the candle emissions page.

Where to go after choosing a soy wax

If your soy candles show white crystals, go to frosting on soy candles. If you are weighing soy against a blend that solves some of these behaviors, compare it on coconut wax and wax blends. And if you have a soy wax and a jar in hand, the next decision is the wick: start at how to size a wick.

References

1. U.S. Patent and Trademark Office, U.S. Patent 6,797,020, Triacylglycerol based wax for use in container candles (inventor Timothy A. Murphy), issued September 28, 2004, full text (claims and description), read October 22, 2026. https://image-ppubs.uspto.gov/dirsearch-public/print/downloadPdf/6797020
2. Google Patents, US6773469B2, Triacylglycerol based wax for use in candles (inventor Timothy A. Murphy; assignee Cargill, Inc.), granted August 10, 2004. https://patents.google.com/patent/US6773469
3. Google Patents, US6503285B1, Triacylglycerol based candle wax (inventor Timothy A. Murphy; assignee Cargill Inc.), granted January 7, 2003. https://patents.google.com/patent/US6503285
4. Voyageur Soap & Candle, Golden Brands GW 464 Soy Container Candle Wax (product page with manufacturer's instructions), undated, read October 22, 2026. https://www.voyageursoapandcandle.com/Golden_Brands_464_Soy_Wax_p/20264.htm
5. CandleScience, CandleScience SimplySoy Artisan Wax (product page), read October 22, 2026. https://www.candlescience.com/wax/candlescience-simplysoy-artisan-wax
6. CandleScience, How to Make a Soy Candle, updated October 27, 2025. https://www.candlescience.com/learning/how-to-make-a-soy-candle
7. CandleScience, Lab Notes: CandleScience Coconut Apricot Wax, undated (images dated April 2024), read October 22, 2026. https://candlescience.com/lab-notes-candlescience-coconut-apricot-wax
8. Village Craft & Candle, Soy Wax vs Paraffin Wax, Erin Parsons, October 23, 2021. https://villagecraftandcandle.com/blogs/news/soy-wax-vs-paraffin-wax
9. Justia Patents, U.S. Patent 7,637,968, Triacylglycerol based wax for use in container candles (references cited list: 6797020, September 28, 2004, Murphy), read October 22, 2026. https://patents.justia.com/patent/7637968