Differences between paraffin and plant waxes
Decisions, decisions… Choosing the wax for your candle can be a major decision. Maybe you’re looking for a wax that is compatible with your brand, or maybe you’re just starting out on your candle making journey and aren’t really sure where to begin. This article will offer some background information, give you a few tips, and explode a few myths. Candle Shack’s range of waxes is extensive and growing - where does a candlemaker begin?
Waxes fall into two general categories – paraffin wax (also known as mineral wax), and plant wax (often referred to as “natural” wax). Not only do these wax types originate from different sources, but they also have different types of chemical structure. Perhaps not surprisingly, they also behave differently in candles. This article will compare and contrast these two types of waxes, thus assisting candlemakers in making informed decisions about which wax suits their brand or hobby.
Paraffin wax is a by-product of the petrochemical industry. In broad terms, paraffin waxes are mixtures of chemicals called alkanes, and are made up of chains of carbon atoms with hydrogen atoms attached to them. The mixtures consist of many different chain lengths, and the chains can be straight or branched. What this means for the candle maker is that different paraffin wax blends will have different properties. Each blend is a unique mixture, so some blends will be softer than others, and the melting ranges will be different. They might have slightly different colours and textures. Typically, the melting ranges will be 46 - 68°C.
After pouring a paraffin wax container candle, the hot liquid paraffin wax will change back to a solid. During this process the wax will crystallise, causing it to contract, and will usually form a dip or cavity in the surface of the candle. The surface can be smoothed by re-melting the top of the candle with a heat gun. However, paraffin wax will not normally have good glass adhesion and will usually pull away from the inside of the candle glass as the candle cures, typically within 24-48 hours.
A popular myth about paraffin wax is that it can be quite smoky when burning in a candle. This isn’t strictly true. Any poorly wicked candle can give a smoky flame, whether it is paraffin wax or plant wax. If a paraffin wax candle is fitted with a suitable wick, it can burn beautifully and cleanly. This is the art of the candle making. Candle Shack’s newest mineral wax is CS1, an exclusive blend that is compatible with most fragrance oils in the Candle Shack collection.
Some candlemakers are uncomfortable with paraffin wax because it is sometimes regarded as non-sustainable. However, it should be borne in mind that crude paraffin wax is simply a useful minor by-product of the oil industry and not its raison d’etre. The reality is that the excellent hot throw from a paraffin wax candle and the ease of obtaining a smooth shiny flat surface almost every time make paraffin the wax of choice for a wide range of international luxury candle brands.
Plant waxes are often referred to as “natural wax”. Let us pause for a moment and think about that. You would be forgiven for thinking that a “natural wax” is a wax that is squeezed from plants in lush summer fields and shipped directly to your supplier. This is only part of the story.
The life cycle of a plant wax begins with the harvesting and crushing of the soy, rapeseed or coconut to extract the oil. The liquid vegetable oil is then chemically purified and filtered. The oil is then reacted with hydrogen gas (a process called “hydrogenation”) to chemically transform the liquid oil into solid wax.
The most common types of plant waxes are soy, rapeseed and coconut. They belong to a class of chemicals called “triglycerides” and chemically they are very different from alkane-based paraffin waxes – this is why they look and perform differently.
The chemical structure of plant waxes shares some similarities with paraffin wax. Plant waxes also contain long chains of carbon atoms, but in plant waxes, three carbon chains are attached to a glycerine molecule through “ester” linking groups. The degree of hydrogenation of the carbon chains will influence the properties of the plant wax - different combinations of carbon chains will affect the hardness and melting point and crystal structure of the wax.
From a candle making perspective, this is important. Plant wax blends typically have lower melting points than paraffin waxes, and when a fragranced container candle is cooled, the “dip” in a plant wax will generally be much less than a similar paraffin wax candle because the crystal structure of the solid wax is different.
The surface of a plant wax candle will often have a “matt” appearance. It can sometimes be difficult to get a good finish on a soy wax fragranced candle, but this can usually be rectified by using a heat gun. Rapeseed blends are increasingly popular and are generally easy to work with and give a good finish.
Coconut wax is too soft on its own to be used as a candle wax, but it can be used in conjunction with soy or rapeseed wax to create plant wax blends with different properties. Plant waxes can also be combined with paraffin waxes to give blends that don’t dip too much when cooling and the surfaces can be flash heated or heated with a heat gun to give a smooth shiny surface on the candle.
A unique feature of plant waxes is that most can be heated in a microwave, making them ideal for small-scale candle making.
Plant waxes are a great option if you want to avoid any association with the petrochemical industry, and plants are more sustainable than paraffin. Soy wax was one of the first plant waxes on the market, and most manufacturers use ethically sourced soy.
Rapeseed is becoming more popular as it is generally farmed in Europe and is therefore not associated with deforestation. Candle Shack’s RCX wax has excellent sustainability credentials as it is made from European rapeseed and coconut that originates from smallholding farmers in the Philippines who are being supported and trained in sustainable farming techniques.