The Bottlecap Trick

by Sheridan Cole 6,992 views0

There are lots of elaborate tricks that will give you a great laugh when you entertain your friends at your favorite watering hole, but simple tricks have their own excellence.  The elaborate trick is vulnerable to interference from audience members joking around, but the simple trick takes care of itself.  Here is a simple trick that is perfectly safe to put in front of a rowdy crowd – The Bottlecap Trick.

The bottle cap trick requires a nice 20-ounce glass bottle and a metal bottlecap. The “metal” quality of the cap is important – a plastic cap won’t do the job.  Most beer bottlecaps are made of metal, and will work well for this trick. The dome shapes of soda bottlecaps won’t do the job, and the plastic won’t bend properly.

The other piece of your equipment should be a longneck glass bottle. You can try it with a shortneck glass soda bottle if you want, or even with a plastic bottle, but you’re putting the life of your trick in grave jeopardy – you’ve been advised! The neck of the bottle is crucial – it will contribute to the airflow that makes the trick work, so experiment with necking at your own peril.

The Steps Involved

First, fold the bottlecap in half.  The metal should bend one way easily, following the curve of the cap’s edge downward.  Bending the cap the other way doesn’t matter – the airflow will be the same. After the first demo of the trick, suggest that maybe the cap could be bent the other way, and enjoy the hunt for pliers that follows!

When you have set the terms of your trick, be it in terms of finance or personal greatness, lay the bottle on it’s side in the middle of a table. The placement of the bottle is not important for the trick’s effectiveness, but if you want to enjoy watching your friends struggle with physics of the trick later on, starting out in the middle of the table gives them a great red herring to pursue.  Place the folded bottlecap in the entry of the bottle’s neck.  It should NOT be placed in too deeply – make sure some part of the cap protrudes out of the bottle. Now tell your friends to blow on the bottlecap and push it inside the bottle. NO TOUCHING THE BOTTLE ALLOWED. When your friends lean over and huff and puff on the cap, they will find it impossible to blow into the bottle, although it will be possible to knock it out of the neck and onto the table!

Airflow is the secret to the trick! The air already inside the bottle has to go somewhere when new air comes in, so it goes right out through the neck, pushing the cap out!  The harder your friends fight to push the cap in, the harder the airflow pushes it out.

Check out the video below for a good look at the trick: