At the Children’s Museum of Houston, we love doing stuff with soda geysers (when you drop Mentos into a 2L bottle of soda to make it spray out everywhere). We even do a red, white, and blue soda geyser salute every 4th of July! So, for the next seven weeks during our O Wow Moments series, we’re going to be looking at Soda Geysers. Now, some people may ask, “Hasn’t this been done already? The Mythbusters did a whole episode on it and there are several videos including the Eepybird one that started it all.” To this I must reply, “Why should they have all the fun?!?” That, and not many people have really explored the anatomy of making the best possible soda geyser.

Of course, in order to do your own explorations at home, you need a way to make a soda geyser. There are several versions out on the market including the Geyser Tube by Steve Spangler and the Eepybird Diet Coke and Mentos Kit. But if you like to work with your hands (like yours truly) and want to spend less than the cost of the premade versions, then here is a way to make your own!

What to Do:

  1. Cut a hole in the top of a twist-off soda bottle cap. I used a Dremel tool to cut mine. The hole needs to pretty much remove the entire cap to give room for the Mentos to drop down into the bottle.
  2. Glue the bottle cap into the 1″ side of a 1″ slip to 3/4″ thread PVC adapter. I used gorilla glue, as it foams up and seals it in nicely.
  3. Cut an 8″-10″ length of 3/4″ PVC pipe.
  4. Next you need to make a trigger mechanism. I used a nail (a 1 1/2 x 16 wire nail from a different project) tied to a piece of string.
  5. Drill a hole about 1″ from one end of the PVC pipe in the center of the pipe that is just big enough to allow the nail to slide through easily. Note that some of the soda will come out the holes, so you don’t want them to be too big.
  6. To the end with the hole in it, attach a 3/4″ thread to 3/4″ slip PVC adapter.
  7. Twist the two adapters together. Why did I use two adapters? I couldn’t find a 1″ slip to 3/4″ slip adapter at my local hardware store.



How to Make It Work:

  1. Put the nail through the hole.
  2. Add Mentos into the pipe
  3. Tighten the unit onto a soda bottle
  4. Stand back
  5. Pull the string! (make sure to get out of the way of the soda coming out the nail holes)



You may have some questions that relate to the other videos in the series, like:

  • Why does the geyser spray out? Check out Episodes 2 and 3 (coming soon)
  • What kind of soda works best? Check out Episode 4 (coming soon)
  • How many Mentos should I use? Check out Episode 5 (coming soon)
  • Does the soda temperature matter? Check out Episode 6 (coming soon)
  • What’s the world record for highest soda geyser? Check out Episode 7 (coming soon)



NOTE: A final addition I did after we shot the video was to add a nozzle. This was done by buying a sweeper nozzle for a garden hose, attaching it to a 3/4″ thread to 3/4″ slip PVC adapter, and then putting that onto the other end of the PVC pipe after loading in the Mentos. This greatly increases the height of the spray!