Gummis. The Gummis were screaming.

By Phil Plait | October 20, 2010 7:00 am

Chemistry is awesome.

Of course, when this experiment is done, you can no longer investigate Gummi anatomy. Such sacrifices are sometimes necessary.

And before I let you go…

<science pedantry>

[Note added later: apparently, according to a few commenters below, the acid I describe is only needed if you don’t heat the perchlorate; they do in fact use a flame in the video. Still, who can resist a bit of chemistry?]

I think the video leaves out an important part: you need a bit of sulfuric acid to make this work. Adding the acid to potassium chlorate yields chloric acid and potassium sulfate:

2 KClO3 + H2SO4 → 2 HClO3 + K2SO4

Sugar reacts, um, strongly to the chloric acid:

8 HClO3 + C12H22O11 → 11 H2O + 12 CO2 + 8 HCl

You can see the water coming out of the test tube in the form of steam — the reaction is highly exothermic — and the purple flame is from potassium being heated. At the same time, a second reaction occurs, breaking up some of the sugar molecules into carbon and water. When the flames and sturm and drang are all done, what’s left is a black residue: carbon, the burnt remains of the tasty, tasty Gummi bear.

</science pedantry>


Comments (37)


    How about trying that with Jelly Babies? 😉

  2. Russ

    A favorite of my high school chemistry teacher

  3. Nemesis

    It had to be my favorite flavor. No fair.

  4. DLC

    Nonsense. the gummi bear burns because it has Sinned Before God and therefore deserves burning. The flames are purple because that’s the color of God’s Anger Chakra.
    Err um… come back when I’ve had more coffee.

  5. Kat

    OMG that was amazing!!! chemistry FTW!!!

  6. JMarton

    Poor Gummi Bears are becoming the unwitting fruit flies of chemistry ed.!

  7. David P

    My high school chemistry teacher would do this all the time. he would even build a story around the gummy bear and then when we answered a question wrong he would “send him to hell”

    We also were alowed to make methane bubbles that were like 2ft diameter and then blow them up.

    That is how you make more kids do chemistry.

  8. Gary Ansorge

    ,,,and the carbon remains behind.

    Gee, maybe I could use this reaction to power my steam engine, while retrieving the carbon for later disposal. Now, all we need is to be able to apply this to coal fired power plants.

    First, convert all the coal to Gummi bears(can’t think of a better use for coal).

    Gary 7

  9. Tim D

    Strap a rocket nozzel on the end of the test tube and you have the answer to all of NASA’s problem. I can see the headlines now…

  10. My high school chemistry teacher would do this with Barbie dolls, alcohol, and (IIRC) some form of potassium. We called it “Barbie Flambé”. (To be fair, he also made “GI Joe Flambé” on occasion.)

  11. Messier Tidy Upper

    There’s another youtube clip here :

    Via (#27.) Noadi on the linked gummi bear anatomy thread :

    Hope that’s okay to quote here.

  12. Messier Tidy Upper

    @10. Tim D Says:

    Strap a rocket nozzel on the end of the test tube and you have the answer to all of NASA’s problem. I can see the headlines now…

    Yup, I was just thinking of gummi bears as the new rocket fuel myself. 😉

  13. Messier Tidy Upper

    In other weird science news (of sorts) see :

    For an R2D2 swimsuit. Now there’s two words I bet you thought you’d never hear combined .. 😉

  14. Chris

    LMAO. I’m thinking of Mr. Bill. Oh no.

  15. Chris

    Actually Phil I’m not so sure about needing the sulfuric acid catalyst. I think you add the H2SO4 when you don’t heat it, that produces the HClO3 which reacts with sugar. Since they are heating the KClO3, it reacts with the sugar because it has enough energy to react.

    I think the HClO3 would decompose at elevated temperatures.

  16. Thomas McCarthy-Ward

    I’ve done this experiment many times, you don’t need sulfuric acid if you melt the potassium chlorate, which is what they do in this experiment.

    It’s the chlorate ion, rather than a specific compound of chlorate that reacts with the sugar. The chlorate doesn’t “care” whether it’s associated with a potassium ion, or a hydrogen atom as in the acid.

  17. MoreBU-Whoohoo!

    The NC State Fair is going on now, and the local paper (News&Observer) had a blurb this morning on A FIVE POUND GUMMI BEAR!!! (

    Can you imagine this experiment with one of those 5lb puppies? Somebody call Burt Rutan – he may have a new fuel source for SpaceShipTwo!

  18. Rory Kent

    Science Pedantry is otherwise known as “Science”.

  19. Georg

    Here is an
    example which is clearly without sulfuric acid.
    But nevertheless the first equation is much too
    simple anyhow. Chlorate and sulfuric acid will
    react to more than just chloric acid.
    (It is the standard laboratory reaction to
    demonstrate chlorine dioxide)

  20. Russ

    David P, the phrase ‘jerkface’ doesn’t by chance mean anything to you, does it?

  21. Todd Boughn

    It’s as if Willy Wonka invented napalm…

  22. JoeSmithCA

    Yeah, I don’t think I’d wanna make a rocket using heated potassium chlorate, sulfuric acid or chloric acid in a hybrid rocket. Might be fun in place of the solid fuel component although I have a feeling that at ingition the engine will fail with a flaming technicolor spray of gummy goo (I’m imagining something gross oozing out the nozzle)

  23. PhilZ

    Just don’t do this with cough drops. The gooey inside will squirt all over. Also works well with any organic material. I had kids volunteer candy, sticks, whatever to see how the reactions would differ.

  24. un malpaso

    Mmmmm… I love the smell of burned Gummi in the morning!

  25. 10. Tim D Says: “Strap a rocket nozzle on the end of the test tube and you have the answer to all of NASA’s problem.”

    Been there, done that. This is basically what’s called “carmel candy” propellant in the hobby. You can even see Homer Hickam and his buds making it in the movie “October Sky.”

    This video made the rounds of the rocket community last week. The biggest concern is that it doesn’t appear that they’re doing this in a fume hood. Notice that in addition to water and carbon dioxide, you’re also getting a healthy dose of hydrochloric acid in that vapor. Not good to be breathing hot HCl.

    – Jack

  26. I'd rather be fishin'

    I do this every year as an example of an oxidizing agent. Never use any acid, just melt the perchlorate compound. I learned after the 1st demo to always use an old test tube, they’re a real pain to clean out….

  27. I'd rather be fishin'

    I do this every year as an example of an oxidizing agent. Never use any acid, just melt the perchlorate compound. I learned after the 1st demo to always use an old test tube, they’re a real pain to clean out….

  28. JB of Brisbane

    What we’re all forgetting here is – did anyone ask the Gummi Bear’s permission? Do you think he’d want to be fried to a crisp in a highly exothermic reaction? This is Gummi Bear Cruelty! I’m dobbing the St Alban’s science department in to PETA 😉

  29. Nigel Depledge

    No fair! I can’t view the video from work!

    Still, this reminds me of my chemistry teacher making expanded carbon, from (IIRC) sugar and conc. sulphuric. A brilliant reaction, and a great way to get kids interested in chemistry.

    Then again, that same teacher demonstrated the thermite reaction in our classroom. Now that was fun. The globules of molten iron spat out by the reaction were small enough that they had cooled down by the time they landed.

    This also reminds me of a lecture tour titled something like “Flashes, bangs and [something else explodey-sounding]”. I never got to attend one of these lectures myself, but apparently the prof soaked some cotton wool in liquid oxygen (according to Brainiac, the “miracle substance”!) and then lit it. It burned so fast that no-one saw the flame – the lecture hall was just suddenly filled with little bits of ash. Then, according to the story, this was once filmed using a high-speed camera so it could be viewed in slow-motion. When they viewed the footage, they saw that the flames actually reached all the way to the back of the lecture hall. After that, he stopped using that particular demonstration.

  30. AndyG

    Important facts:
    1) No, no acid required.
    2) Put all the compounds away *before* doing the reaction.
    3) Obviously works much better with Jelly Babies because they’re British!
    4) Never let the kids choose which colour to toast, things can get very dodgy!
    5) The “commercial” British sugar-powered rocket works in a similar way but is a much much bigger firework with a propotionately bigger ‘oooooh’ factor.
    6) Never do this experiment with more than one Jelly Baby … the rest are for eating when the kids are not looking :-)

  31. Richard

    My high school chemistry teacher did this with a box of Red Hots. It was like he had lighted a flare under the fume hood.

  32. baxter

    get a fumehood bro.

  33. anon

    LOL!! Ah, how nostalgic. Screaming Jelly babies~

  34. Excited

    Yes! This means we can finally have gummi bear fueled cars!

  35. timone

    did this with a starburst…the whole test tube exploded into dust!

  36. Manu

    Ya. Potassium Perchlorate will react with a gummi bear just fine if you melt the perchlorate before adding the bear. It also leaves a nice freshly toasted marshmallow scent in the air.


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