Fizz-Keeper facts for kids

The Fizz-Keeper is a small hand pump designed to help keep your soft drinks fizzy. It screws onto the top of a plastic soda bottle. People who sell the Fizz-Keeper often say that pumping air into the bottle stops the drink from going flat.

However, scientists have studied how the Fizz-Keeper works. They found that pumping air into the bottle does not stop your drink from going flat. It might slow down the process a little bit, but it won't keep your soda bubbly for long.

What is a Fizz-Keeper?

The Fizz-Keeper is a simple device. It has a small pump that you use by hand. You attach it to the top of an open plastic soda bottle. Then, you pump air into the bottle. The idea is to increase the pressure inside the bottle. This increased pressure is supposed to keep the carbonation (the fizz) from escaping.

The first device similar to the Fizz-Keeper was invented a long time ago, in 1926, by G. Staunton. The actual Fizz-Keeper was patented in 1988 by T.R. Robinson and M.B. Beyer. There are different types of Fizz-Keepers. Some are just simple pumps. Others have a special spout that lets you pour the drink without taking the Fizz-Keeper off the bottle.

How Does it Work (or Not Work)?

When you open a soda bottle, the fizz (which is carbon dioxide gas, or CO₂) starts to escape. This is why your drink goes flat. The Fizz-Keeper tries to stop this by adding more air pressure to the bottle. But does it actually work?

The Science Behind the Fizz

Scientists explain that the fizz in your soda is carbon dioxide gas dissolved in the liquid. When you open the bottle, this gas wants to escape into the air. This process is called "going flat."

Even if you pump more air into the bottle with a Fizz-Keeper, it doesn't stop the carbon dioxide from leaving the drink. Think of it like this: the carbon dioxide molecules don't care about the other air molecules (like nitrogen and oxygen) that you pump in. They still want to escape from the liquid until the amount of CO₂ in the air above the drink matches the amount in the drink itself. This idea comes from something called Dalton's law, which is about how gases behave. So, adding more air doesn't change how much CO₂ stays in your drink.

Does it Really Keep the Fizz?

While the Fizz-Keeper doesn't stop your drink from going flat, it can slow down the process a little. The increased pressure from the pump makes it a bit harder for the carbon dioxide to escape quickly. However, this effect is very small. It might keep your drink a little fizzier for a few hours, but not for days. So, if you're hoping to keep your soda fresh for a long time, the Fizz-Keeper isn't the best solution.

Fizz-Keeper for Fun and Learning

Even if it doesn't keep your soda perfectly fizzy, the Fizz-Keeper is still useful! It's a great tool for home science experiments and for learning about physics. You can use it to explore how pressure works and how gases behave.

Many science teachers and experimenters have used the Fizz-Keeper in their lessons. For example, Rohrig has written a book with science experiments you can do using a Fizz-Keeper. Other scientists like Moloney, Spangler, Graham, and Williams have also shared experiments using this simple device. It's a fun way to see science in action!

See also

In Spanish: Fizz keeper para niños