Several years after it first appeared on the market, rapeseed wax does not hide its ambition to become the de facto environmentally responsible candle wax. And it could very well succeed, even though it's rather difficult to work with and does not always have the visual appeal other waxes do.
Here's a short overview of this newcomer in the world of candle waxes that is gaining more and more followers as time goes by. The fact that it's marketed as a vegan friendly, kosher, halal, free of palm oil and of GMO's is probably one of the reasons for its growing popularity.
Rapeseed is widely and commonly grown in Europe and, together with the sunflower and the olive tree, is one of the main sources of food grade vegetable oil on our continent. You have more than probably marveled at the stunning sight of vast, bright yellow fields while you were driving through the countryside: rapeseed plants as far as the eye can see.
Unlike soy that is massively imported from the American continents where it is routinely genetically modified (about 70% of cultivated soy is the GMO type) and without any doubt one of the causes of global (and often unregulated) deforestation, rapeseed, grown locally and in a logic of crop rotation, has a low environmental impact. Even more so when you compare it to that of other vegetable oils used to manufacture candle making waxes, like the aforementioned soy but mainly palm wax, created from palm oil, the atrocious environmental credentials of which are or should be well known.
As is the case with most vegetable waxes, an industrial process called hydrogenation is necessary to turn rapeseed oil into a substance that is solid at room temperature, therefore rending it usable to make candles, or at least container candles as these benefit most from a soft, low melt point wax. It is also how most rapeseed waxes are used, even though blends for pillar candles and wax melts are available.
Rapeseed oil is a potential allergene. It's a good idea to check whether you are unaffected before you purchase a 50 pounds bag of it.
Be aware that if you purchase a rapeseed-based pillar blend, it will always be blended with another type of wax or with one or more additives to give it the hardness required to achieve decent pillar candles. In some cases, a vegetable grade stearic acid is used, in other cases beeswax. Sometimes, the added ingredients are not disclosed, making it difficult to honestly market your candles as "natural". Rapeseed wax for pillar candles is usually sold in pellets or powder form.
But it's container candles that represent the largest market share of rapeseed wax, its very nature making it particularly apt to be poured into glasses, tins and other containers. Depending on the manufacturer, the final product can contain rapeseed only or, as it's usually the case, be a blend of rapeseed and another vegetable wax. The most popular blends are that of rapeseed and coconut or rapeseed and soy.
Rapeseed wax can also be used as an additive to "soften" other vegetable waxes.
As I mentioned in the introduction, you don't work with rapeseed wax like you do with soy wax. Rapeseed wax is a bit sensitive and likes to be treated with a certain amount of attention, care and respect.
As an example, to melt it, you have to heat it to a temperature of at least 140°F but never above 167°F if you don't want to damage its crystalline structure. So you probably want to use the double boiler technique and melt the wax very slowly, constantly monitoring its temperature. The container (assuming you're making a container candle) will have to be at least at room temperature but preferably heated to around 113°F. Adding dye to the wax happens around 158°F (some solid dyes will not melt under that temperature) and adding fragrance oil is best done between 131°F and 140°F. Finally, pouring into the (still at 113°F) container is done at a rather low temperature. Manufacturers often mention 122°F but experience shows that a lower temperature (as low as 101°F) gives better results. Let the candle cool off as slowly as possible in a room that is not chiller than 68°F.
Rapeseed wax has a natural inclination to display some level of frosting at its surface and will often develop cracks; following the instructions relative to the different temperatures will help minimize these symptoms but not eliminate them completely. Surface cracks can usually be mended using a heatgun but other than that, these imperfections are like the signature of rapeseed wax and the price to pay if you want to use a truly natural and environmentally responsible wax.
Once poured, it is recommended to let your container candles cure for at least a week at room temperature before using them.
The wick you use will be an average of two sizes above what you would normally use in a soy wax container candle of the same size / diameter. The ideal wick for rapeseed wax is one in the TCR series.