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Everyone knows that you have to blow out the candles on your birthday cake to get your wish. But what if you blow out the candle and it…magically relights itself? Cue confusion, and maybe a little mortification as the people around you snicker at your baffling situation. Later, a prankster will tell you that it was a trick candle, and you will feel a sense of relief for not forgetting how to blow out a candle. Using a trick candle on a birthday cake is an excellent prank for both young and old alike. But like you, we began to wonder, “How do trick candles work?” It’s all in the science behind the flame.


Short answer: There is a chemical added to the candle wick that allows the wick to reignite. With a trick candle, after you try to blow the candle out, the wick is able to relight at the lower temperature than normal because of the chemical added to the candle. And it doesn’t matter how hard you try, that wick will continue to reignite until someone douses the candle in water.

But what is the exact science? How do trick candles work in a strictly scientific sense?

Let’s start with this: the chemical usually added to trick candles that makes them so frustrating is magnesium. Magnesium is a compound with a low ignition temperature and one that is highly reactive to heat and oxygen. You might think that could cause a birthday cake explosion, but trick candles are crafted with just enough magnesium that all you really get is a candle that just won’t go out. The magnesium is added to the wick of a trick candle. When you try to blow the candle out, the magnesium coated wick is exposed to heated oxygen from the smoke of the candle which makes the magnesium spark and instantly reignites the candle.

It’s a pretty simple explanation for a cool parlor trick. But you might be surprised that the wick shouldn’t be getting all the attention. After all, even for regular candles, the wick isn’t what makes the candle burn for such a sustained amount of time. What deserves the credit? Wax.


That’s right, all that fuss about special wicks making trick candles work is cool and all, but it isn’t the wick that deserves recognition for burning candles. The real credit should go to a severely under recognized modern marvel: paraffin wax.


You might be surprised to learn that the wick of a candle isn’t actually on fire, but the wax of the candle itself. Paraffin wax is currently the most common wax used to make candles, specifically because this petroleum byproduct allows candles to burn for a long time. With candles, the wick plays the role of absorbing the liquid paraffin wax and delivering that wax to the flame atop the wick. While the wick does get hot and a little singed, it takes a long time to burn because the evaporating paraffin wax keeps the wick cool.

Basically, when you light a candle you are introducing a catalyst to melt just enough wax to get the candle going. Once the wax begins to melt, the flame has a continuous source of fuel so long as it is exposed to air. Heat, fuel, and oxygen are all that is needed to make a candle burn.


Remember when we said that magnesium is added to the wick of a trick candle and that’s why trick candles keep igniting even after you blow them out? That’s still true even if the star of the candle-burning show is paraffin wax. We already know that regular candle wicks absorb the paraffin wax that acts as fuel for the wick. We also know that the magnesium coated wick of a trick candle is highly reactive to heat and oxygen.

So how do trick candles work? While a trick candle is burning, the magnesium in the wick is protected by the liquid state of the melting paraffin wax. However, once that wax is no longer melting, it begins to give off the heated vapor we perceive as smoke from the wick. That heated vapor is just hot enough to cause the chemical chain reaction between the sparking magnesium, a heat source reintroduced to the paraffin-absorbing candle wick, and a newly burning flame that again feeds off the melting paraffin wax.


There are a lot of trick candles on the market, but some are more common than others. Your average trick candle will be ones designed for birthday cakes, where every candle represents a year of someone’s life. These trick candles are usually two or three inches tall, kind of skinny, and usually have a striped design. We like these candles for how large the pack is and how well the candles reignite.

These trick sparklers are a fun alternative to a traditional trick candle. Instead of a steady burn, these candles provide a fun sparkler that operates on the same magnesium wick principle.

There are of course more adult-themed trick candles. These candle clips are a hilarious nod to the fact that many adults would rather have a cocktail than a cake. The candle simply clips onto the side of a glass so that you are blowing out a glass rather than a cake. You can add any kind of candle you want to these clips, but trick candles would be the funniest.

No matter which kind of trick candle you pick, you can be sure they all operate by the same basic scientific methods. It might look like magic, but the trick to trick candles is all about magnesium and wax.


When you look into a question like, “How do trick candles work?”, you inevitably start thinking about other things. Like, are trick candles safe to use? Knowing how trick candles work on a scientific level should help ease most concerns. After all, we know that there isn’t enough magnesium in a trick candle to introduce a reaction larger than a few sparks. But does that make a trick candle safe? Here are a few things to know about safety for trick candles.


A trick candle is no more dangerous than a regular candle. More frustrating? Sure. More funny? Obviously. But more dangerous? Absolutely not.

The only difference between a regular candle and a trick candle is the magnesium, right? And while you might not want to get your face so close to a trick candle when you blow it out, you can rest assured that trick candles will not burn you or create large enough sparks to cause an injury. Trick candles are more or less some of the safest fire-related pranks around, which is why you can buy trick candles from online retailers. Just like any other candle, when the candle is inert and not burning, it’s just another hunk of wax.

That said, trick candle packages have directions on the back of the package that outline recommended uses and how to put the candles out as a standard safety precaution. Always make sure to read package directions just to be on the safe side.


While trick candles are all in good fun, we know that good fun is always had when everyone stays safe. For that reason, a lot of trick candles have packaging that declares an age limit. Most trick candles have a five years and up limitation for the sake of safety, mostly because children under five have a tendency to squish their faces into their birthday cakes, which isn’t advisable when there is a chemical reaction continuously happening with the candle.

That said, some states have stricter age limits on trick candles, so it is always important to double check your state laws. A good indicator that your state has stricter trick candle laws is if trick candles are not sold in stores or cannot be shipped to your state. And when in doubt, make sure to check any for any age limit labels on candle packaging.


How do trick candles work? Trick candles aren’t all that different from regular candles. The science behind the flame is all about the magnesium coating the wick, which reacts to the paraffin vapor as soon as you try to blow the candle out. Both regular and trick candles rely on paraffin wax absorbed into the wick to burn, but the difference is that regular candles don’t instantly spark from paraffin vapor the way trick candles do. Trick candles rely entirely on science to work, even if that science does look like magic.

Trick candles will continue to play tricks until doused with water or burned to the bottom of the wick, which makes for a long-lasting and good-natured prank. There are many different kinds of trick candles, so if you search long enough you will definitely find one to suit your needs. As to safety concerns, trick candles are just as safe as regular candles so long as the user is over the age of five. Always be sure to check the safety ratings and your state laws before purchasing trick candles.

Trick candles are excellent pranks for any occasion, but are especially fun for birthday parties. Put the trick candles in the cake, light the candles, and watch as someone tries to make a wish on a candle that just won’t blow out!

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