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How Can You Clean Black Candle Glass?

Aug. 03, 2022

When you notice a thin gray film forming on the top of the container, you have been burning the candle and falling in love with this new fragrance. Each burn makes the buildup worse until a black ring appears on the top of the candle. Although unsightly, there is a perfectly normal explanation for this black deposit, and it is easy to prevent and clean. Read on to learn what causes candle glass to turn black, how to prevent it from happening and how to remove the buildup.


Why do candle jars turn black?

When you light a candle for a while and start to notice black crawling on the side of the candle jar, this is carbon at work. The flame produces carbon, and the bigger the flame, the more carbon there is.


The blackness you see in the jar is due to a lack of oxygen. The jar can only produce carbon without the necessary flow of oxygen, and then it burns. The updraft of these hot gases from the combustion starves the flame of oxygen and prevents the diffusion of air.

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This causes a general burnt black appearance inside the candle. Unless you are an amateur candle maker, you may not be aware that there are actually proper ways to combat the burning of carbon that produces the black, burnt appearance we all hate so much.


Candle glass darkens due to soot buildup. Soot can occur in any type of candle but is more common in certain types of wax, such as paraffin. Soot is produced as a result of an incomplete combustion reaction and it can be caused by several different factors. One of the main causes is a candle flame that is too large, which in turn is caused by a longer wick. Longer wicks and larger flames mean that more wax will be melted, thus providing more fuel for the candle. This increased fuel can lead to incomplete combustion, which results in carbon smoke.

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Marble Tea Light Candle Holder

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Uneven combustion also produces soot. Long wicks tend to curl or mushroom at the top, which can create a lumpy flame that burns some parts of the candle wax better than others. The wick may also be off-center as the wax melts, which can also cause an uneven burn and soot. Finally, placing the candle in or near a vent can cause the flame to move around, again leading to uneven burning and more soot.


The right way to burn

Believe it or not, there is more to burning a luxury candle than just lighting the wick and letting it go. Sure, you can do that, but you'll probably end up with those black marks on the side of the jar pretty quickly. First, when you first use it, you should burn it for about two hours or so. This will help extend its life and make sure you can use it again and again. Doing this will allow the top layer of wax to melt completely.

The top layer melting will even promote burning when you light it next.

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How can I prevent the candle glass from turning black?

Thankfully, soot formation is not inevitable and there are several steps you can take to prevent it from forming, even before it starts. The first is to trim the candle wick to an eighth to a quarter of an inch before each burn (make sure the candle is completely cool before doing so). You can use scissors to start, but you may want a special wick trimmer so that you can continue to do this while the candle burns. Trimming the wick will help prevent incomplete burning by keeping the flame small and making sure it is evenly shaped. You can find the high-quality candle jars, click here.


If the wick moves during the burning process, you should also reposition it while the wax is still soft. You can use a wick trimmer or other tool to push it back into place. Do not use your fingers, as you may burn yourself. You should also keep the candle away from vents, drafts, and other things that could cause the flame to sputter or burn unevenly. Place the candle in a safe location where it will not be disturbed. It is normal for the candle flame to wobble a little, but if it does go in and out, or is unevenly shaped, try moving the candle to a new location.

Soy Wax

Soy Wax


How do I clean the black candle glass?

Despite your best precautions, soot may form on your soy wax candles. If your candle glass becomes black, it is best to clean it regularly to prevent soot buildup. The more soot there is, the more difficult it will be to clean. Before cleaning your candles, blow out the flame and allow the wax and container to cool completely. Wet a paper towel and rub it on the soot until it dissipates. If the soot is really stubborn, you can use topical alcohol instead, which will eliminate the buildup. Allow the candle to dry completely before burning again.


If you have burned the candle very low and want to re-purpose the jar, you can also remove the candle wax with soap and water. First, you need to remove the candle wax from the jar. Soak the candle container in some soapy water and then wipe it with a soft cloth until all the soot comes off. Let the container dry before reusing it.


Don't be afraid if all of your candles have black soot rings. This unsightly buildup is easy to prevent and clean up. Follow these tips to keep your candles soot-free and looking good.