While candle making isn’t rocket science, we can all agree that candle making is still a science that requires some trial and error to create a product that you can be proud of. If you’ve ever tried making candles, chances are you have experienced at least one of the following common candle making problems. Here we will explore some of the regular issues that candle makers face, explain what causes them and offer guidance on how to correct and prevent the issue.

Wet Spots

Candles go through multiple temperature changes throughout their life cycle. For container candles, anytime the temperature becomes cooler, there is a chance that the wax will contract and pull away from the sides of the jar. They typically happen in candles made of soy, paraffin, palm and beeswax, but are less likely to occur in softer waxes like coconut and softer paraffin waxes. Stopping wet spots from ever happening is nearly impossible.
While there is really no way to prevent wet spots, there are a few things you can do to discourage them:

• Wash your glass and dry thoroughly before using to ensure there isn't any kind of film or build up that could affect glass adhesion.
• Make sure the room where your candles are curing is not too cold and keeps a consistent warm temperature.
• Preheat your glassware in a warm oven or with a heat gun. This will allow the candles to set as slowly as possible. Hot wax being poured into a cold container is more likely to have poor glass adhesion than warm wax being poured into warm containers.
• Pour the wax slowly into the container to avoid air bubbles from being created.
• Tap your jar gently after pouring to help release any air bubbles.
• Leave space between jars (around 4") to ensure that your candles set evenly on all sides.
• Put your candles on a wire rack as opposed to a solid surface, which can pull heat from the bottom of the jar and cause the candle to set unevenly.
• Try using a softer wax or blending one into your harder wax making it less likely to contract and pull away from the glass. (ie Coconut or 4630 paraffin wax)

Even if you create the perfect candle with perfect glass adhesion, wet spots can occur at any point during transportation, shelf-life, or in a customer’s care.  Remember, wet spots are only cosmetic and don't impact the performance of your candle in any way.

Frosting

Frosting is a natural occurrence in soy wax. It's caused by crystals forming in the wax mainly due to temperature fluctuations and time (also known as Polymorphism). Wax blends like Freedom soy have been created with additives mixed into the wax to help the wax resist its natural frosting tendencies. Unfortunately, even with a wax blend we can't guarantee that frosting will never occur. The following techniques can help reduce the appearance of frosting in your candles:

• Make sure to mix your wax slowly after adding fragrance and/or dye.
• Heat your containers on a low temperature in the oven or by blasting them with a heat gun prior to pouring your candles.
• Allow your soy wax to cool as much as possible in your pour pot prior to pouring your candles.
• Leave your candles their natural colour as dyes can make frosting more noticeable.
• Modify your wax by adding paraffin or coconut wax to reduce the chance of crystals forming in it causing frosting.
• Cure at room temperature and keep away from windows and drafts that will cause it to cool more quickly.
• Place your candles on a wire cooling rack because solid surfaces can absorb heat from the candle and cause the wax to cool too quickly.
• Hide the problem with frosted, dark coloured or opaque containers. Wrap around labels would also work.

Bumpy “Cauliflower” Tops

Just like with frosting, bumpy tops (aka “Cauliflower tops” due to their strong resemblance to the surface of a cauliflower) are caused by polymorphism. It occurs in wax during the temperature fluctuations that take place while the liquid wax is cooling and changing back into a solid. If no preventative measures are taken and the wax is left to cool on its own, it will cool unevenly throughout the candle. This means that the wax on the top, sides and bottom will have ample opportunity to form those troublesome crystals while the centre continues to cool and set. Here are some tips on how to prevent it from happening as well as how to fix it if it does occur.

• Allow your wax to cool as much as possible in your pour pot before pouring it into your containers. Be sure to stir the wax slowly as it cools to keep the temperature as uniform as possible throughout the wax. When it starts to become cloudy, you are ready to pour
• Heat your containers in the oven on a low temperature or by blasting them with a heat gun prior to pouring your candles to avoid cold jars causing your candles to set unevenly.
• Keep your jars warm as they set so that they set slowly and evenly throughout. You can do this by wrapping each jar in tin foil, putting them in an insulated box, setting a box over top of them, etc.
• Ensure that the room your candles are kept in is warm, not humid and isn’t draughty (ie no open windows or ceiling fans).
• Soy wax is very prone to bumpy tops, so blending it with another type of wax like coconut or paraffin can help stabilise it and smooth out its finish.
• If you do all these things and still end up with bumpy tops, use a heat gun or hair dryer to melt around 1/8” of wax at the top of your candle and it should reset much smoother.

Unfortunately, after going to all this trouble, your candle will most likely end up with the same bumpy top after it is burned for the first time. The good news is that it won’t affect how your candles burn and most customers aren’t concerned with how the top of their candle looks as long as it smells great and burns safely.

Flame is tiny or self extinguishes

It is so frustrating when you go to the trouble of creating a beautiful candle only to end up with a very small flame or no flame at all when you test burn it. What could have gone wrong?! There are several possibilities to explain why your wick isn’t burning properly and we’ll examine them below:
 

1. Wick trimmed too short: If a wick is trimmed too short it can burn down to the wax before enough of a melt pool has been created for fuel.

• Solution for this candle: Dig out enough wax that there is at least ¼” of the wick above the surface of the wax and the candle top is as flat as possible all the way across.
• Solution for future candles: Be sure not to trim your wick shorter than ¼”.

2. Wick wasn’t primed: If a wick wasn’t primed with wax prior to making your candle, the bare string can burn down to the surface of the candle too quickly to create a melt pool for fuel and extinguish itself.

• Solution for this candle: Dig down exposing ¼” of wick and rub a small amount of wax onto the wick for fuel prior to relighting.
• Solution for future candles: If your wick does not say that it is primed, you will need to dip it in melted wax prior to making your candles.

3. Clogged wick: For a candle to burn properly, wax must be able to be drawn into and up the wick to the flame for fuel. Everything you put into your wax will get drawn into the wick along with the wax. If something that you have added to your wax is not able to move up the wick and be burned off by the flame, it will end up clogging the wick. When the flame does not receive a consistent supply of fuel, it will become smaller and may even go out.

• Solution for this candle: Unfortunately, there really isn’t a way to save your candle. The only thing that you will be able to salvage is the jar by melting the wax out of it.
• Solution for future candles: First you will need to determine what is causing the blockage. It is a good idea to test your wick in a candle with no additives in it first to be sure that the wick works in the wax you are using. Once you have determined that, you should make a series of candles adding back 1 additive at a time. This will help you figure out which one was the clogging substance. Some common wick clogging additives include mica, glitter, crayons, powdered pigment, propolis in beeswax, certain fragrance oils and essential oils.

Tunnelling

When your wick burns a hole down into the candle and the melt pool never reaches the edge, this is known as tunnelling. There are 2 main reasons this happens.

1. Wick is too small: The first is because the wick that you have chosen is not large enough to create enough heat to melt the wax all the way to the edge of the candle. There really isn’t an easy fix to save your candle in this scenario. The only thing that you could do to salvage your wax and jar is to remelt the wax in an oven on low. You would then dump the wax into a pour pot, remove the wick and clean the jar. Then you will start over with a larger sized wick. To keep it from happening in the future, you will need to test some larger wicks until you find one that creates a melt pool that reaches all the way to the edge of your candle. While your wick suppliers’ recommendations are a great place to start, the only way to know for sure that your wick will work in your candle recipe is by testing it for yourself.

2. Improper burn: The other reason is because you did not burn your candle long enough for the melt pool to reach the edge before extinguishing it. When your candle starts to tunnel because of this, you can try correcting it by burning it for an extended period and hope that it is able to melt away the wax ledge on its own. If it continues to tunnel, you will need to remove the wax ledge by digging or cutting it off creating a flat surface on your candle. Before relighting your candle, make sure that you will have enough time to allow your melt pool to reach all the way to the edge of the candle. To give you an idea of how long that will take, a properly wicked candle will burn out approximately 1” in diameter per hour. Therefore, if your candle is 3” wide, you will most likely need to burn it for at least 3 hours before it reaches the edge.

“Mushrooming” Wick

The little black mushroom shaped formation that sometimes appears at the top of a wick is a build up of carbon. It is caused by something interfering with the combustion process. It’s impossible to guarantee that your candles will never have mushrooming and small carbon build ups are not a huge reason to panic. However, if you are seeing large carbon balls consistently form on your candles, it is worth looking into what could be causing them. Here are some of the things that can cause a carbon build up:

• The wick was too long when it was lit. In this case you would extinguish the flame and trim it to 1/4” before relighting it.
• The wick is too large for the diameter of the candle. An oversized wick will deliver more fuel to the flame than it is able to consume. Another sign that your wick is too large for your candle is a deep and wide melt pool from the excess heat being created.   
• The fragrance or fragrance load. It is possible for certain fragrances and fragrance loads to interfere with combustion. It’s very wise to do a wick test on a scent free candle first before you start adding many different fragrance oils. This will show you how different oils can affect wicks in different ways. Some wicks don’t handle high fragrance loads well, and you may need to either adjust the amount of oil used or choose a different wick for that scent.
• The wick is not compatible with the candle recipe. There is no guarantee that one wick will work in every candle recipe you make. If you find that the wick is the right size and was trimmed to the right length, it is possible that the type of wick is simply not compatible with the wax, fragrance oil or dye that was used. It is a good idea to be comfortable working with a few different types of wicks.
• Environmental reasons. Sometimes a wick forming a mushroom can be caused by the environment it is being burned in. For example, if there is a draft in the room or a ceiling fan, the extra oxygen can trigger the incomplete combustion. Hotter temperatures can also result in mushrooming sometimes.

Discolouration

We all know that adding fragrance oil to your candle will give it a beautiful scent, but did you know that it may also add a less than desirable colour to your candle as well? Fragrance oils are made up of many different ingredients both natural and synthetic. When these ingredients have a colour to them, they can in turn add a colour to your candles. Natural ingredients that are known to discolour wax include cinnamon and citrus.
A very common synthetic component that is well known for discolouring candles is vanillin. Vanillin is an organic compound that is found in vanilla and makes up 80% of its flavour. Natural vanilla/vanillin is scarce and expensive, so scientists have found a way to synthesise vanillin in a laboratory for a much lower cost. Vanillin is used in many fragrance oils because it is such a nice compliment to other ingredients. It adds a lovely, sweet, and warm element to a scent.
Unfortunately, oxidation can cause vanillin to take on a beige to brown colour when exposed to light and oxygen. Over time your candle will darken in colour because of this. The only way to stop this from happening is to use fragrance oils that have little to no vanillin in them. You can also try to camouflage the problem by dying your candle wax or by pouring your candles into containers that are opaque, coloured or frosted.

Poor Scent Throw

Probably the biggest issue faced by candle makers is a poor scent throw, and it is also the most difficult to diagnose due to the many variables that can affect a candle’s scent throw. Here are a few things that could be causing your candle to have a diminished scent throw:

1. Type of wax: Some types of wax are denser than others and this causes their particles to not be able to be thrown as far as other less dense wax particles can be. Their density will also cause them to not linger in the air as long either. Paraffin is a very light wax which is why it tends to provide a better scent than soy which is a very dense wax in comparison.
2. Type of fragrance oil: Every fragrance oil is made up of many different materials which will cause their scent to vary from one oil to the next. Components that are more volatile will hit you first and then burn off quickly while the less volatile components follow and linger longer. That is why a good fragrance oil needs to be well balanced. The top notes (more volatile) will hit you very quickly and dissipate fast while the mid and base notes (less volatile) will follow and remain leaving the lasting impression. When they are not balanced, the scent throw can either disappear too quickly to spread or take a long time to gain momentum.
3. Type of wick: Your candle needs to have a wick that is just right for the wax you have chosen and the diameter of the candle. If you select a wick that is too hot, it will burn off all the scent before you have had the opportunity to enjoy it. If your wick is too small, it won’t be able to heat the wax enough to release the scent and disperse it.
4. Amount of fragrance oil: Some might think that if your candle has a poor scent throw, you should just add more fragrance oil to improve it. This is not necessarily the case. A candle will use the fragrance oil as fuel for the flame, and if there is too much in your candle it could cause the flame to burn hotter. The additional heat can result in the scent throw smelling more like jet fuel than what it was intended to smell like. It is important to have the proper balance of each component in your candle system to get the best scent throw. Be sure to check the maximum scent load for the wax you are using.
5. Curing: In general, it is recommended that you cure a candle for at least 2 weeks after it is made before burning it. This is important because a candle will continue to harden and condense after it is made. As it does this, the fragrance molecules will continue to be dispersed evenly throughout the candle.
6. Subjective: Scent is a very subjective thing. It is completely possible to burn a candle that one person thinks smells amazing, another thinks is way too pungent and yet another who can hardly smell it at all. You need to keep this in mind when selecting your fragrances. Unfortunately, it’s simply not possible to please everyone all the time.

Oily wax

If you notice that your candle has an oily surface or liquid in the bottom of the container, it means that your fragrance oil is leaking out of the wax. There are 2 reasons for this:

1. Didn’t bind properly. You must make sure that you are heating the wax to a hot enough temperature that it will bind well with the fragrance oil. Every wax will have a recommended temperature to reach prior to adding the fragrance oil. If you don’t heat the wax enough before adding the scent, you will likely be able to see the oil floating around in the wax. If this happens, continue to heat the wax on a low temperature and stir gently until you can no longer see the oil.
2. Fragrance oil overload: Every wax has a maximum amount of fragrance oil that is recommended. If you happen to add too much, this can result is oil leaking out of your finished candle. Make sure not to exceed the maximum fragrance oil load to avoid this.

Conclusion

Every candle maker is striving for the same thing, to make the perfect candles. Unfortunately, there are many different variables that can influence how your candles will turn out. While it is not possible to control every possible scenario, there are things that you can do and adjustments you can make to help control your end results. Keep experimenting until you get it right.