How to Make a Vortex in a Bottle




About: In a valiant attempt to keep myself from dying of boredom, I create.

We have had one of these around the house for years.  Our grandchildren, of all ages, love to watch the water swirl from the top bottle to the bottom bottle.  Our 2 ½ year old grandson would bring it to one of us, to have us swirl it, over and over again.  The first time I saw this principle used in life was when a Marine swirled a bottle of wine into a punch bowl, at a military wedding. It was way cool then, just as cool now.  Here is How to Make a Vortex in a Bottle.

Teacher Notes

Teachers! Did you use this instructable in your classroom?
Add a Teacher Note to share how you incorporated it into your lesson.

Step 1:

2 straight walled, 2 liter bottles with caps
5 minute epoxy (about $4.00 at craft stores)
Electrical tape
Small paper cup
½ drill bit
Large nail
Sand paper, medium grit
Food coloring  (your choice of color)

Step 2:

Here is the safety precaution:  Be careful when using the drill, the epoxy and the lit candle.  If you are a Kid under age 18, have an adult help you with this project.  If you are an adult, use common sense when making this project. 

Clean the labels off the 2 liter bottles.  Leave the white plastic ring on the bottle. It will help hold the caps in place when you are ready to make a vortex.

Step 3:

Use the sand paper to smooth down the tops of the two caps.  These caps are not level so try to make them as level as possible.  They do not need to be perfect. The sanding isn’t so much as to make the tops smooth, but to rough up the tops so that the epoxy will stick to them.

Step 4:

There are two ways to make the hole between the caps.

1.  Using the drill, drill a hole in each cap.  Match the holes up and then mix the epoxy in the small paper cup, with the toothpick.  

Step 5:

Use the toothpick to spread the glue, gluing the two caps flat sides together, with the holes aligned , cover all around exposed areas with epoxy. Put it on the inside of the hole and around the outside of the caps.  It doesn’t have to be perfectly smooth or even.  When hardened, stretch the electrical tape around and around the cap to hold it tight and keep it sealed.

Step 6:

2.  Mix the epoxy in the small paper cup, with the toothpick.  Use the toothpick to spread the glue, gluing the two caps flat sides together, and cover all the exposed areas, including the outside of the caps.  Let harden.  When hardened, stretch the electrical tape around and around the cap to hold it tight and keep it sealed.   Light the candle and use the pliers to hold the large nail.  Stick the pointed end of the nail in the flame until red hot, and use the hot end to melt a hole through the two caps.  Reheat the nail as often as needed to make a nice sized hole between through the two caps.  It doesn’t have to be perfectly smooth or even.

Let the cap sit for 12 hours to cure.

Step 7:

Fill one of the bottles over ½ full of water.  Put food coloring into the water.  The vortex will be easier to see when the water is colored.

Step 8:

Screw the cap on to the bottle with water in it.

Step 9:

Turn the empty bottle upside down and screw it into the top of the cap.

Step 10:

Now you are ready to create a vortex-in-a-bottle.  Turn the bottles upside down with the water filled bottle on top, give it a good swirl, and make sure it is stable on the bottom bottle.  Enjoy your vortex.

Step 11:

Some suggestions have been made to add glitter to the water, or use oil and water instead of plain colored water.  Experiment on your own, and have FUN!

The Mad Science Fair

Finalist in the
The Mad Science Fair

ShopBot Challenge

Participated in the
ShopBot Challenge

Be the First to Share


    • CNC Contest

      CNC Contest
    • Make it Move

      Make it Move
    • Teacher Contest

      Teacher Contest

    51 Discussions


    I really have no idea. No insult taken. Appearantly, an editor saw this instructable and chose to feature it. Thanks for looking.


    Reply 7 years ago on Introduction

    Well, I i kind of went - "Huh?" myself. Seems rather obvious for a feature piece. Then again is IS pretty cool, and anything that gets new people interested in science is definitely worthwhile!

    Side note - I used to work in a HS science lab, and used distilled water to prep most of the chemistry. Flipping a 5 gallon water jug's spout into the 20 gallon large bottle - the water would take a while to flow from the 5 on top down into the 20 below. Glub --- glub --- g l u b -- g l u b .....

    To speed up the transfer process, I used to give the full 5 gallon on top a quick swirl, which set up a vortex and allowed the entrained air in the lower jug to move up through the restriction while the water in the top jug flowed down and filled the main one. Every so often the kids would glance into my prep lab and see the tornado, and their eyes would go wide.


    Reply 3 years ago

    Tilting the bottle to let air pass at same time takes far less effort.


    Reply 7 years ago on Introduction

    Like I said, no offense taken. I know the reaction I get from it from my grown children and grandchildren. I am still not sure what I did right to get it noticed. Thanks for looking.


    7 years ago on Introduction

    then are we north or south of the equator ?…

    when I went to Brasil I was dumb enough not to have checked which side water turned when emptying from a tub in Europe, so when I got there I never really found out !!!…

    childish, isn't it ?… (I'm 63 !!!!…)

    1 reply

    Reply 7 years ago on Introduction

    Does the vortex speed up as it runs or is it constant speed once it gets going? Maybe you could add some particles of something so we could tell this in the video?

    5 replies

    The speed will increase until the liquid's viscosity limits the speed it can go, then it will go the same speed from then on.

    You can go faster with a fluid of lower viscosity or if the bottle is larger diameter.

    I was right the first time, according to the law of conservation of angular momentum, if it was going as a constant speed, but over a shorter distance, it would look like it is speeding up, when in reality it is going a constant speed. Bernoulli's Principle has more to do with air than liquids.

    You're right it would look faster, but it actually does go faster as it spirals in as well.

    Angular momentum is speed times distance from the axis, and the distance has gone down, so conservation means it must have speeded up!

    It's like tornadoes, that's how they get such incredibly high wind speeds.

    I will not be redoing the video any time soon, but I did drop a plastic bead into the bottle and watched it swirl. It seems to be affected by Bernoulli's Principle. As it approached the contriction in the neck of the bottle it sped up. If I had thought it through more completely, I would have realized it that would be true. Thanks for looking.

    I really don't know! I think that it goes down at a constant speed. I will need to do some thinking, maybe put tick marks down the side of the bottle and see how fast the water moves from one tick mark to the next. Let me think. Why don't you create one perform your own experiment? Thanks for looking.


    7 years ago on Introduction

    so, how do you keep the water from all running out of the top bottle while you are swirling it up? and what effect does changing the hole size have?

    2 replies

    If you turn the bottle upside down, the water slowly glug, glug, glugs it's way down ward. You have plenty of time, to get the water to swirl before it all goes down the spout. You can experiment with the hole size, the larger the hole the larger the base of the vortex. Pretty basic. If you want, you could make a square hole and see how that works, that would make a great experiment and I would love to hear about the results. Thanks for looking.

    ok, I made mine today. I'm thinking of trying smaller bottles for the next one. 2 litre's seem a bit cumbersome

    instructables 026.JPGinstructables 027.JPG

    Reply 7 years ago on Introduction

    The maker of that video contacted me based on the you tube video of the vortex. Right now Iam revamping how I make them and will up grade my Instructable. Thank you so much for sharing, and thanks for looking.


    7 years ago on Introduction

    My mother taught me how to empty a bottle faster, by using a rotating wrist movement causing a vortex while holding the bottle upside down.

    1 reply

    Reply 7 years ago on Introduction

    That's what some bottled beer drinkers do in competitions. It allows the displacement of air without the glugging effect. They swirl then quickly turn the bottle, open the epiglottis and pour straight down.