sugar and yeast balloon experiment

Science Bob

• Experiments
• Science Fair Ideas
• Science Q&A
• Research Help
• Experiment Blog

more in Experiments

Blow up a balloon with yeast, you will need.

A packet of yeast (available in the grocery store) A small, clean, clear, plastic soda bottle (16 oz. or smaller) 1 teaspoon of sugar Some warm water A small balloon

1. Fill the bottle up with about one inch of warm water. ( When yeast is cold or dry the micro organisms are resting.) 2. Add all of the yeast packet and gently swirl the bottle a few seconds. (As the yeast dissolves, it becomes active – it comes to life! Don’t bother looking for movement, yeast is a microscopic fungus organism.) 3. Add the sugar and swirl it around some more. Like people, yeast needs energy (food) to be active, so we will give it sugar. Now the yeast is “eating!”

4. Blow up the balloon a few times to stretch it out then place the neck of the balloon over the neck of the bottle. 5. Let the bottle sit in a warm place for about 20 minutes If all goes well the balloon will begin to inflate!

How does it work?

As the yeast eats the sugar, it releases a gas called carbon dioxide. The gas fills the bottle and then fills the balloon as more gas is created. We all know that there are “holes” in bread, but how are they made? The answer sounds a little like the plot of a horror movie. Most breads are made using YEAST. Believe it or not, yeast is actually living microorganisms! When bread is made, the yeast becomes spread out in flour. Each bit of yeast makes tiny gas bubbles and that puts millions of bubbles (holes) in our bread before it gets baked. Naturalist’s note – The yeast used in this experiment are the related species and strains of Saccharomyces cervisiae. (I’m sure you were wondering about that.) Anyway, when the bread gets baked in the oven, the yeast dies and leaves all those bubbles (holes) in the bread. Yum.

MAKE IT AN EXPERIMENT

The project above is a DEMONSTRATION. To make it a true experiment, you can try to answer these questions:

1. Does room temperature affect how much gas is created by the yeast? 2. Does the size of the container affect how much gas is created? 3. What water/room temperature helps the yeast create the most gas? 4. What “yeast food” helps the yeast create the most gas? (try sugar, syrup, honey, etc.)

More Images & Video

More from my site

ADS (these ads support our free website)

Share this page.

Yeast and Sugar Science Fair Project

40 Comments

In this Yeast and Sugar Science Fair Project, we’ll watch yeast feed on sugar to fill a balloon with air. A fun science project for kids that’s with household, everyday materials.

Our Inspiration

I’ve been baking bread just about every day for the past three weeks (nothing too crazy since it’s all done in the bread maker), but last week my 3.5 year old and I got into a discussion about the properties of yeast.

We like to tinker and  experiment — big surprise, I know — and decided to see what would happen if we mixed yeast with warm water.

My preschooler took this job very seriously, poured the water into a bowl, added a couple teaspoons of yeast, and waited a few patient minutes before she said, “it makes a brownish color.” True, and to make it bubble like it does in bread, we needed to activate it with sugar.

What’s so great about an experiment like this is that it’s easy to do with household materials, and it’s ripe for authentic child-generated questions and observations. When I asked what she thought would happen if we added sugar to the yeast she said, “I don’t know! Let’s mix them and find out!.”

Supplies: Yeast and Sugar Science Fair Project

• Sugar, 2 tablespoons
• Active Dry Yeast, 1 packet or 2 1/4 tablespoons
• Warm water (105-115 degrees F, 40.5-46 degrees C)
• Mixing bowl + funnel
• Bottle that you can fit a balloon over

Mix the yeast and sugar into the warm water and stir. I noticed that N was sniffing the concoction and asked her what it smelled like. She said “poop.” I could see what she was saying. Consider yourself warned.

Once it all dissolves, pour the mixture into the bottle and cover the bottle with the balloon.

After a few minutes you’ll be amazed by something like this!

Will it blow off the bottle?

N wanted to feel it as it filled with air. She noticed the balloon was getting bigger and wanted to know how big it would get, wondering out loud, “will it fill up all the way and blow off the bottle?”

Good question!

My handy-dandy ship captain sister (no joke — that’s her job!) was visiting, and put herself right to work as chief measurer.

Move it to a safe spot

Once the bottle filled up completely, we moved the whole yeast sugar experriment to the sink. The bubbles were slow-moving, and there was nothing to worry ourselves with, but N enjoyed pulling the balloon off and watching the foam slowly pour over the bottle’s top.

Ideas for Extending this Experiment

As we went through the process, I thought of a few fun extensions for older kids or those who want to take this further. You could play around with food coloring/liquid watercolors, have a few bottles going at once and compare the results of different sugar:yeast ratios, or compare the results of different water temperatures.

I found my recipe at The Exploratorium’s Science of Cooking series, where we also learned that as the yeast eats the sugar it makes carbon dioxide, which is essentially the same process that yeast goes through in our bread dough.

Mmmmm. I’m off to eat some whole wheat cranberry walnut oat bread. Toasted. With butter and Maldon salt. How do you like your bread? And have you played around with yeast concoctions?

More Science Experiments for Kids

If you enjoyed this project, you’ll love this article:  Science Fair Project Ideas .

What a great idea!!

Thanks, Deborah 🙂

thank you soooooooooooooooooooooooooooo much for this info

I used to bake a lot of bread with my boys when they were younger (pre-celiac diagnosis) and they always loved my scientific explanation of why the bread rises: the yeast eats the sugar and farts. 🙂 That’s what all the bubbles are, of course!

Yep, farts would be another not-so-pretty way to describe this process. Between that and my daughter’s description, I’m not sure if anyone will want to try this themselves 😉

we love yeast! my son thinks of yeast as little pets. here is our experiment we did a few months ago. it seems to come up ever year or so. great post!

http://mamascouts.blogspot.com/2011/09/science-experimentwake-up-yeast.html

Thanks for sharing your yeast experiments, Amy! I love them, and we have to try this with maple syrup next time (if I can convince my MS-adoring family to part with it first!).

way cool! you know I like to tinker as well with my girls – this will be something we can easily do at home.

I pinned this! 🙂 thanks for sharing!

Thanks for pinning it, Bern 🙂 And yes, I can totally imagine your two little scientists going crazy over this one!

This is the best blog for experiments! Thanks for sharing all your great ideas.  Linking up to it in a science for preschoolers post. 

Hi Kristin, Thank you soooooo much for the kind words about Tinkerlab. And thanks for sharing us with your readers….feel free to send me a link if you’d like and I’ll share it on Facebook.

This is so fun! We did this today and the kids loved it. Thank you!

awesome, lindsie! i’m thrilled to hear it was successful. thanks for taking time to give me this update.

Hmmm…sugar, yeast and water…also known as Kilju or sugar wine! https://en.wikipedia.org/wiki/Kilju

As well as CO2, yeast and sugar also produces Ethanol (alcohol). Probably best not to teach the kids that part though!

That’s funny, Chris. I’m sure that my 4-year old won’t be least bit interested in sugar wine!

Point taken. Out of interest, did you ever find out what made the “poop” smell? In theory it should just produce CO2 which doesn’t smell.

could i add flour to the mixture. would it have the same effect ?

it’s nice

moooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooo

why soooooooo many o’s sara

What quantity of water did you use? I’m doing an adaptation of this for my science assignment

Miguel Cabrera

What were the measurements for each balloon

Thanks for this great post. We did this today while baking bread. My boys loved measuring the baloons often and seeing what would happen.

[…] is a safe activity for preschoolers and toddlers because you are using edible materials. Moreover, kids will see, touch, and smell while observing, […]

Thanks Nice Experiment

I don’t get it, it does not have a video!

[…] Blow Balloon With Yeast Experiment […]

Is this supposed to be 2 1/4 TEASPOONS or TABLESPOONS. Your instructions say one packet of yeast (which is 2/4 teaspoons) but you wrote 2 1/4 tablespoons. Thanks for any clarification you can provide

* my comment should read that one packet of yeast is 2 1/4 teaspoons

Comments are closed.

TinkerLab is a creative studio dedicated to sparking curiosity and a love for art through hands-on making. Our mission is to inspire creativity and experimentation in makers and artists of all ages, transforming everyday moments into creative adventures.

USEFUL LINKS

Testimonials

Privacy Policy

Terms & Conditions

GET IN TOUCH

855 El Camino Real

Suite 13A-144

Palo Alto, CA 94301

10 WAYS TO INTRODUCE ART TO PRESCHOOLERS

An inspiring 10-point poster for your fridge, planning binder, or to share with colleagues or friends.

TinkerLab acknowledges the ancestral land of the Muwekma Ohlone Tribe, and pays respect to elders both past and present. This land was and continues to be of great importance to the Ohlone people, and we have a responsibility to acknowledge, honor and make visible the our relationship to Native peoples. Donate to the Association of Ramaytush Ohlone. 

Inflate a Balloon with Yeast Experiment

Did you know that you can inflate a balloon WITHOUT blowing air into it? It’s true.

In this simple experiment , young scientists use yeast to magically inflate a balloon. How cool is that?!

Check out the simple step-by-step below and then snag our 30 Science Experiments that are kid-approved!

Getting Ready

We headed into the kitchen to grab all of our supplies for this science experiment:

• Clear plastic or glass bottle with a narrow neck (a water bottle or soda bottle work great)
• 2 Tablespoons dry yeast
• 1 Tablespoon sugar
• 2-3 Tablespoons lukewarm water
• Party balloon
• Bowl or mug full of lukewarm water

Inflating a balloon with yeast is a wonderful experiment to do with preschool and kindergarten aged children because all of the materials are nontoxic. It’s nice when the kids can help measure out ingredients without worrying about what they are touching.

My kids helped me measure the yeast, sugar, and warm water into a cup.

They stirred the ingredients and then used a funnel to pour the brown mixture into the bottle. We added a little bit more water to help the yeast mixture get through the neck of the funnel.

We quickly stretched a balloon over the mouth of the bottle.

After placing the bottle into a mug full of warm water, we sat back to observe.

Inflate a Balloon with Yeast

Almost immediately, we observed bubbles in the yeast mixture.

I explained to the kids that yeast is a microscopic fungus that converts sugar into carbon dioxide.

The bubbles they saw were tiny bubbles of carbon dioxide gas that the yeast was producing as it “ate” the sugar.

For yeast to be active, it needs to be warm and moist. That’s why we added lukewarm water and placed the bottle in more warm water.

We set our bottle of yeast on the table and watched it while we ate lunch and read books.

We checked in with our science experiment every 10 minutes or so to observe any changes. Every time we looked, we noticed that the balloon was getting bigger and bigger on top of the bottle! Why?

As the yeast continued to react, it converted more and more sugar into carbon dioxide gas.

This gas was trapped in the balloon, making it inflate as if by magic!

It took about an hour for our balloon to reach its maximum size.

The yeast bubbled up into the bottle quite a bit before it stopped reacting and shrank down again. Simple science at its best.

More Fun for Little Scientists

Grab our 30 Science Experiments in our shop – complete with a no prep journal to record results!

Similar Posts

Apple Tree Counting Cards

STEM Supply Labels

Pumpkin Patch Addition Cards

Pot of Gold Base 10 Blocks

Gingerbread Pattern Cards

Crystal Heart Valentine’s Science Experiment

One comment.

• Pingback: Delma Childers : Young Academy of Scotland

Leave a Reply Cancel reply

Your email address will not be published. Required fields are marked *

• Science & Math
• Sociology & Philosophy
• Law & Politics

Inflate a Balloon with Yeast Fermentation Experiment: Lab Explained

• Inflate a Balloon with Yeast…

INTRODUCTION

Yeasts are eukaryotic, single-celled microorganisms that belong to the fungal kingdom. When yeasts consume sugar and convert it to energy, they emit carbon dioxide, this is referred to as fermentation. The yeast will be more active and develop faster if there is more sugar present. While sugar and other sweets provide “food” for yeast, too much sugar can harm it by draining moisture from it and preventing it from growing. Too much sugar also delays the development of gluten. Increase the amount of yeast in the recipe or find a comparable recipe with less sugar.

Sweet yeast doughs will rise more slowly. Fermentation is sped up by a small amount of sugar, up to 3%. Warm water makes yeast grow, cold water has the reverse effect, and hot water kills yeast. Temperatures ranging from 0 to 47 degrees Celsius are suitable for yeast growth. Yeasts flourish in acidic settings with pH levels between 4.0 and 4.5. They can grow in lower pH environments than other bacteria, but not in alkaline environments. Yeasts are common in nature and can be found on grapes and other fruits. All yeast need food, moisture, and a controlled temperature environment in order to ferment. Its byproducts from food consumption include carbon dioxide, alcohol, and other organic molecules.

comparing yeast growth at various sugar concentrations.

• 50ml of water
• Two balloons

(funnel may be needed to safely transfer the ingredients into the water bottles)

• A kettle was used to boil the water, then cold water was added to the boiling water to get lukewarm water.
• 50ml of lukewarm water was added to each bottle.
• ¼ teaspoon of table sugar was then added to the first water bottle, then ½ teaspoon of table sugar was added to the other water bottle.
• ½ teaspoon of rapid-rise yeast was then added to each solution and mixed.
• After mixing, a balloon was placed on each water bottle/ tube and sealed securely.
• The contents were mixed periodically.

(N.B- A string may be used to seal the balloon placed on water bottles).

OBSERVATIONS

During the experiment, 500ml water bottles were used. Then 50ml of lukewarm water was added to each bottle, after that, ½ teaspoon of sugar was added to the 1 st bottle then ¼ teaspoon of sugar was added to the 2 nd bottle. Finally, ½ teaspoon of rapid-rise yeast was added to both bottles, then the balloons were placed on each tube and securely sealed. The balloons were checked at the time interval of 15min to observe any changes, when glancing at the balloons, it was noticed that the balloons were getting bigger and bigger every time on top of the water bottles. Warmth and moisture are necessary for yeast to function, that is why lukewarm water was added. Sugar was converted to carbon dioxide by yeast.

Some bubbles were also observed in the yeast mixture during the experiment, it was the small carbon dioxide gas bubbles produced by the yeast as it “ate” the sugar.

As the yeast continued to react, additional sugar was transformed into carbon dioxide gas. The balloons were filled with this gas, which caused them to inflate. It was also observed that the balloon on the water bottle that had ½ teaspoon of sugar was growing bigger at a faster rate than the one that had ¼ teaspoon of sugar.

This can show that glucose concentration increases fermentation production in yeast. The more sugar present, the more active the yeast becomes, and the faster it grows. The balloon on the bottle that had less sugar was growing at a slow rate compared to the other one, even had fewer bubbles visible. It was seen that the concentration of sugar plays a vital role in the rate of fermentation, the more sugar present, the more active the yeast becomes, and the faster it grows. This also showed why the fermentation rates of the sugars differ over time. Both balloons grew until they reached a point where they grew no more.

During the experiment, when the balloons were growing bigger and bigger, using the time interval of 15 minutes, the circumferences of the balloons were measured. From the measurements, it can be safely concluded that the balloon on the water bottle with ½ teaspoon of sugar grew bigger and faster than the one on the water bottle with ¼ teaspoon of sugar. Another thing observed is that as time went by the fermentation rate of both the balloons started to decrease.

From what was observed during the practice of the experiment, it can be concluded that the more sugar there is, the more active the yeast will be and the faster its growth. THIS CAN BE APPLIED IN REAL LIFE: fermentation can be used to preserve food, preventing rotting or harmful microorganisms from growing in the food. Can also apply when baking bread.

Related Posts

• Lab Explained: Production of Yeast Fermentation
• Molecular Weight of Air Lab Explained
• Drake’s Equation Explained

I would like to cite this article for a research paper, would it be possible to disclose the authors name(s), and date this was published?

Leave a Reply Cancel reply

Your email address will not be published. Required fields are marked *

Save my name, email, and website in this browser for the next time I comment.

Post comment

Yeast-Air Balloons

The purpose of any leavener is to produce the gas that makes bread rise. Yeast does this by feeding on the sugars in flour, and expelling carbon dioxide in the process.

While there are about 160 known species of yeast, Saccharomyces cerevisiae, commonly known as baker's yeast, is the one most often used in the kitchen. Yeast is tiny: Just one gram holds about 25 billion cells. That amount of fungi can churn out a significant amount of carbon dioxide, provided it has the simple sugars it uses as food. Fortunately, yeast can use its own enzymes to break down more complex sugars—like the granulated sugar in the activity below—into a form that it can consume.

Make a yeast-air balloon to get a better idea of what yeast can do.

Did You Know?

What do i need.

1 packet of active dry yeast

1 cup very warm water (105° F-115° F)

2 tablespoons sugar

a large rubber balloon

a small (1-pint to 1-liter) empty water bottle

Kids, please don t try this at home without the help of an adult.

What do I do

Stretch out the balloon by blowing it up repeatedly, and then lay it aside.

Add the packet of yeast and the sugar to the cup of warm water and stir.

Once the yeast and sugar have dissolved, pour the mixture into the bottle. You ll notice the water bubbling as the yeast produces carbon dioxide.

Attach the balloon to the mouth of the bottle, and set both aside.

Step 5: After several minutes, you ll notice the balloon standing upright. If you don t see anything happen, keep waiting. Eventually, the balloon will inflate.

What's going on.

As the yeast feeds on the sugar, it produces carbon dioxide. With no place to go but up, this gas slowly fills the balloon.

A very similar process happens as bread rises. Carbon dioxide from yeast fills thousands of balloonlike bubbles in the dough. Once the bread has baked, this is what gives the loaf its airy texture.

What Else Can I Try?

Try the same experiment, but this time use about a tablespoon of baking powder instead of yeast, and leave out the sugar. What differences do you notice? Which leavener takes longer to fill up the balloon?

Also, try the same experiment using hotter and colder water. Use a thermometer to measure the temperature of the water. At what temperature is the yeast most active? At what temperatures is it unable to blow up the balloon?

• Skip to primary navigation
• Skip to main content
• Skip to primary sidebar

• FREE Experiments
• Kitchen Science
• Climate Change
• Egg Experiments
• Fairy Tale Science
• Edible Science
• Human Health
• Inspirational Women
• Forces and Motion
• Science Fair Projects
• STEM Challenges
• Science Sparks Books
• Contact Science Sparks
• Science Resources for Home and School

Blowing Up Balloons Respiration Style

June 18, 2012 By Emma Vanstone 5 Comments

We’ve talked about respiration before when we made bread and used yeast to make the dough rise. Blowing up a balloon with yeast is another very easy experiment to demonstrate respiration in action and is quicker than making bread if you are short of time.

What is respiration?

Respiration is a chemical reaction which occurs in animal and plant cells. It releases energy from glucose. Aerobic respiration needs oxygen, but anaerobic respiration doesn’t need oxygen.

Anaerobic respiration produces less energy than aerobic respiration. It occurs in humans when not enough oxygen reaches muscle cells ( for example, during hard exercise ). Bacteria and other microorganisms can also use anaerobic respiration, and yeast actually carry out an anaerobic process called fermentation .

Respiration occurs in the mitochondria of cells. You can find out more about mitochondria by making a model of a cell .

Blow up a balloon with yeast

A small clear drinks bottle

A packet of dried yeast

1 teaspoon of sugar

Instructions

1. Blow the balloon up a few times to give it some stretch. This just makes it easier for the experiment to work.

2. Fill the small bottle about 3cm full of warm water.

3. Add the yeast and 1 teaspoon of sugar.

4. Place the balloon over the open top so no air can escape.

5 Over the next half an hour, watch what happens. (Obviously, do other stuff and come back, it may be a little boring to actually watch it for half an hour!)

Yeast and Respiration

Yeast is a living organism. In order for it to survive, it needs to make energy. In its dried form, the yeast is dormant, but as soon as you provide it with warmth, water and sugar (its food), it ‘wakens’ and becomes active. The yeast uses the sugar (glucose) and oxygen from the bottle to make water, energy and carbon dioxide. Carbon dioxide is a gas, and this is what you see filling the balloon.

Remember, yeast can respire anaerobically when there’s not enough oxygen for aerobic respiration.

Fermentation

Glucose -> ethanol and carbon dioxide + energy

Aerobic Respiration Equation

Glucose + Oxygen –> Carbon Dioxide + Water + energy

The image is taken from Snackable Science which contains SEVENTY fun edible experiments and investigations!

Science concepts

Respiration

Contains affiliate links

Last Updated on May 3, 2023 by Emma Vanstone

Safety Notice

Science Sparks ( Wild Sparks Enterprises Ltd ) are not liable for the actions of activity of any person who uses the information in this resource or in any of the suggested further resources. Science Sparks assume no liability with regard to injuries or damage to property that may occur as a result of using the information and carrying out the practical activities contained in this resource or in any of the suggested further resources.

These activities are designed to be carried out by children working with a parent, guardian or other appropriate adult. The adult involved is fully responsible for ensuring that the activities are carried out safely.

Reader Interactions

June 18, 2012 at 3:04 pm

Oooh I like this one a lot! I am storing them all up for rainy days but I’ll get to this one quite quickly!

June 18, 2012 at 6:32 pm

What a cool project! Do the balloons float, then, like helium?

June 21, 2012 at 3:21 am

That’s so cool! We love everything science! My kids will love this!

June 25, 2012 at 8:14 pm

Brilliant experiment!!!! The kids will love it!

Thanks for sharing on Kids Get Crafty!

Maggy & Alissa

March 31, 2013 at 9:18 am

all the experiments simple and kids could easily understand the concepts behind it.

Leave a Reply Cancel reply

Your email address will not be published. Required fields are marked *

• Skip to primary navigation
• Skip to main content
• Skip to primary sidebar

Yeast Balloon Experiment

Updated: Sep 29, 2022 · This post may contain affiliate links.

Can you inflate a balloon with yeast? You sure can! Let's learn how with this simple and fun science experiment for kids.

Yeast Balloon Experiment - Step by Step

What did we learn, expand the experiment, more stem activities for kids.

When you think of yeast, you probably think of baking. But this little ingredient makes for some great science experiments as well!

This yeast balloon experiment is:

• A fun STEM activity for kids of all ages.
• Simple to do with ingredients you probably already have!
• Quick, easy and fun.

Start by filling a large mixing bowl with warm water. It only needs to be lukewarm - not very hot.

Next mix instant yeast, sugar, and warm water together in a glass bottle or flask with a narrow neck (like this Erlenmeyer Flask) . If you don't have one, you can use any bottle or container with a narrow neck. Even a disposable water bottle will work in a pinch. You need to be able to stretch the balloon over the opening!

Place the glass bottle into the bowl of warm water to keep it warm. Stretch the balloon over the opening of the bottle.

Sit back and watch what happens! You should see the balloon slowly begin to inflate. How long does it take for the balloon to inflate?

Yeast is a living organism! And it loves to eat sugar. As the yeast consumes the sugar in your mixture, it converts the sugar into alcohol and carbon dioxide gas. The balloon inflates from the carbon dioxide gas!

This is the same process that is at work when you bake bread or other baked goods with yeast. The yeast consumes sugar, and releases carbon dioxide, which causes your dough to rise. Cool, huh?

Try the experiment a few more times, with varying amounts of sugar and yeast. What combination inflates the balloon to the largest size? Why do you think that happens?

Try again using cold water instead of warm water. Does the balloon still inflate? Why or why not?

If you love this yeast balloon experiment, check out these other fun activities for kids:

• Microwave Ivory Soap - An Easy Experiment!
• STEM Activities for Elementary Kids
• Best Science Experiments for Kids

• 2 tbsp instant dried yeast
• 1 tbsp sugar
• 2 tbsp warm water
• additional warm water
• large mixing bowl
• glass flask or bottle with a narrow neck

Instructions

Fill a large mixing bowl with warm water. Mix the instant yeast, sugar, and 2 tbsp warm water together in the glass bottle or flask. Place the glass bottle into the bowl of warm water to keep it warm. Stretch the balloon over the opening of the bottle. Wait and watch the balloon inflate!

The water should be warm enough to activate the yeast, but does not need to be very hot.

Recommended Products

As an Amazon Associate and member of other affiliate programs, I earn from qualifying purchases.

Love this project?

Pin it to share or save for later!

Reader Interactions

What do you think leave a comment. cancel reply.

Your email address will not be published. Required fields are marked *

Save my name, email, and website in this browser for the next time I comment.

Playing With Rain

Explore the World Around You

in Instagram Feed · Kids Science Experiments

Yeast Balloon Experiment

Share with your friends!

Check out this super cool experiment that uses the expanding power of yeast to inflate a balloon! You and your kids will love doing this Yeast Balloon Experiment together.

Get more amazing Balloon Science Experiments here!

This is a mind-blowing (and balloon blowing) way to learn about the common reaction of yeast, sugar, and water!

Table of Contents

This post may contain affiliate links. As an Amazon Associate, I earn from qualifying purchases.

Supplies Needed:

• A Plastic Bottle

How to Inflate a Balloon With Yeast

• Fill a plastic bottle with about 1 inch of warm water.
• Pour in about 1 tablespoon of yeast and gently shake the bottle up a little bit.
• Add a teaspoon of sugar and swirl the bottle around a little more.
• Slide the neck of the balloon over the opening of the bottle.
• Let the yeast work its magic for about 15-20 minutes. The balloon should slowly start to inflate!

Step 1: Pour Warm Water Into a Plastic Bottle

I prefer to use a clear plastic bottle for this so that you can see the reaction of the rising yeast inside, but you really can use any type of small empty water bottle for this.

The important part is to pour enough warm water into the bottle so that that the water is about an inch deep inside the bottle.

If you bake with yeast often, then you will already know that the water needs to be warm, but not too warm or it will kill the yeast (I had to learn this from my wife who does the baking in our family).

Step 2: Add Some Yeast Into The Bottle

If you have the small little packets of yeast, you can dump one of those into the bottle, or you can measure and pour about 1 tablespoon of yeast from a large packet of yeast.

Using a funnel will make this a little easier and a little less messy to get the yeast inside the bottle.

Step 3: Add Some Sugar

Measure and pour about 1 teaspoon of sugar into your bottle of yeast and warm water. Again, using a funnel will help you get less sugar on the counter and more sugar into the bottle.

Step 4: Attach The Balloon to The Bottle

Quickly, but carefully connect a large balloon to the opening of the bottle. It may help to inflate and then deflate the balloon first just to stretch it out a little bit.

Then slide the mouth of the balloon over the opening of the bottle. Make sure the balloon is snug and sealed onto the bottle to prevent any air from escaping between the bottle and the balloon.

Give the bottle a little swirl or shake to mix the warm water, yeast, and sugar together. This should start the classic yeast reaction that we need for this experiment!

Step 5: Wait Patiently For The Reaction to Inflate The Balloon

The hardest part of this experiment is waiting 15-20 minutes for the reaction to happen and inflate the balloon…but I promise it will be worth it!

So set the balloon and bottle in a safe and secure place, go grab a snack and come back in a few minutes to check on it.

You can also try doing what I did and setting up your phone or camera for a time-lapse video of the reaction. It’s super fun to go back and watch the reaction inflate the balloon with the time-lapse.

After a good 15 or 20 minutes, the yeast, water and sugar should have reacted and expanded inside the bottle, and the balloon will inflated too!

Yeast Balloon Experiment Conclusion

The science behind this yeast balloon experiment is related to the same reason yeast is used in many bread, dough, and baking recipes!

Yeast is a single-celled organism described as a “sugar-eating fungus”. Yeast needs food, warmth, and moisture to thrive and grow.

As the yeast grows and converts the sugar into energy, it releases Carbon Dioxide gas in a process called fermentation .

The tiny little carbon dioxide (CO2) gas bubbles get trapped in bread dough as it bakes and is what makes bread so soft and spongy!

Now in our experiment, the warm water in the bottle provides warmth and moisture for the yeast, while the sugar provides the food for the yeast to grow and expand.

The addition of carbon dioxide in the bottle increases the air pressure in the bottle, which pushes air into the balloon and inflates it!

This Baking Soda and Vinegar Balloon Experiment is also another fun way to inflate a balloon if can’t find any yeast in your kitchen cabinets!

PIN THIS EXPERIMENT FOR LATER

More Fun Experiments For Kids:

• Dancing Grapes Experiment
• How to Make a Bottle Gun
• Cloud in a Bottle Experiment With Rubbing Alcohol

Leave a Reply Cancel reply

Your email address will not be published. Required fields are marked *

Save my name, email, and website in this browser for the next time I comment.

MORE ABOUT PLAYING WITH RAIN

LET’S CONNECT

Search for more ideas, create at your own risk.

All content on this blog was created for inspiration and entertainment purposes. Creating anything with the suggested tools, products or methods, is under your own risk!

Get Your ALL ACCESS Shop Pass here →

Yeast Fermentation Experiment

Fermentation is a fascinating process that kids can easily explore through a simple experiment using yeast and sugar. This hands-on activity teaches students about fermentation and introduces them to the scientific method, data collection, and analysis.

Investigate how different types of sugar (white, brown, and honey) affect the rate of yeast fermentation by measuring the amount of carbon dioxide (CO₂) produced.

Example Hypothesis: If yeast is added to different types of sugar, then the type of sugar will affect the amount of carbon dioxide produced, with white sugar producing more CO₂ than the others.

💡 Learn more about using the scientific method [here] and choosing variables .

Watch the Video:

• Active dry yeast
• White sugar
• Brown sugar
• Measuring spoons and measuring cups
• Small bottles or test tubes
• Rubber bands
• Ruler or measuring tape
• Notebook and pen for recording data ( grab free journal sheets here )
• Printable Experiment Page (see below)

Instructions:

STEP 1. Prepare a yeast solution by dissolving a packet of active dry yeast in warm water according to the package instructions.

STEP 2. Label 3 bottles and add 1 tablespoon of white sugar to the “White Sugar” bottle. Add 1 tablespoon of brown sugar to the “Brown Sugar” bottle. Measure 1 tablespoon of honey and add it to the “Honey” bottle.

STEP 3. Measure and pour an equal amount of the yeast solution into each bottle, ensuring the yeast is well mixed with the sugar.

STEP 4. Quickly stretch a balloon over the mouth of each bottle. Secure the balloons with rubber bands if needed. Ensure the balloons are sealed tightly to prevent CO₂ from escaping.

STEP 5. Place the bottles in a warm, consistent environment to promote fermentation.

STEP 6. Observe and record the size of the balloons at regular intervals (e.g., every 15 minutes) for 1-2 hours. Use a ruler or measuring tape to measure the circumference of each balloon.

TIP: Note the time it takes for the balloons to start inflating and the differences in balloon size over time for each type of sugar.

STEP 7: Analyze the data by comparing the amount of CO₂ produced (balloon size) for each type of sugar. Create a graph showing the balloon size over time for each sugar type.

STEP 8. Determine which sugar type resulted in the most and least CO₂ production. Discuss possible reasons for the differences, considering what each sugar is made of. Think about whether the results support or disprove the hypothesis. Can you come up with further experiments or variations to explore other factors affecting yeast fermentation?

Free Printable Yeast and Sugar Experiment Project

Grab the free fermentation experiment worksheet here. Join our STEM club for a printable version of the video!

The Science Behind Yeast Fermentation

For Our Younger Scientists: Yeast is a type of fungus that feeds on sugars. When you mix yeast with sugar and water, it starts to eat the sugar and convert it into alcohol and carbon dioxide gas. The gas gets trapped in the balloon, causing it to inflate. This shows that fermentation is happening!

Yeast fermentation is a biological process where yeast converts sugars into alcohol and carbon dioxide (CO₂) in the absence of oxygen. This process is used in baking, brewing, wine making and biofuel production. How much fermentation occurs can vary depending on the type of sugar used.

Yeast contains enzymes that break down sugar molecules through a series of chemical reactions . Here’s how it works:

Enzymes are molecules, usually proteins, that act as catalysts to speed up chemical reactions within living organisms.

First the yeast is mixed with warm water, and it becomes activated. The warm environment “wakes up” the yeast cells, preparing them to consume sugars.

Yeast cells produce enzymes that break down sugar molecules (sucrose, glucose, and fructose) into simpler molecules. This process is called glycolysis. During glycolysis, sugar molecules are converted into pyruvate, releasing a small amount of energy.

In the absence of oxygen (anaerobic conditions), yeast cells convert pyruvate into ethanol (alcohol) and carbon dioxide gas (CO₂). The carbon dioxide produced during fermentation is what inflates the balloons in the experiment.

Different Sugars & Fermentation

Different sugars can affect the rate of fermentation. This is how:

• White Sugar (Sucrose): Composed of glucose and fructose and is easily broken down by yeast, leading to efficient CO₂ production.
• Brown Sugar: Contains sucrose along with molasses, which includes minerals and additional nutrients. May result in a slightly different fermentation rate due to its composition.
• Honey: Contains a mixture of glucose, fructose, and other components. The additional components can influence the fermentation process, potentially leading to different CO₂ production rates compared to pure sucrose.

The amount of CO₂ produced depends on how easily the yeast can break down the sugar molecules and convert them into ethanol and CO₂. Sugars that are more readily broken down by yeast will typically produce more CO₂ faster.

More Fun Science Experiments

Explore chemistry , biology and more, including…

• Bread Mold Experiment
• Baking Soda Balloon Experiment
• Bread In A Bag
• Elephant Toothpaste
• Mentos and Soda

Helpful Science Resources To Get You Started

Here are a few resources that will help you introduce science more effectively to your kiddos or students and feel confident presenting materials. You’ll find helpful free printables throughout.

• Best Science Practices (as it relates to the scientific method)
• Science Vocabulary
• All About Scientists
• Free Science Worksheets
• DIY Science Kits
• Science Tools for Kids
• Scientific Method for Kids
• Citizen Science Guide
• Join us in the Club

Printable Science Projects For Kids

If you’re looking to grab all of our printable science projects in one convenient place plus exclusive worksheets and bonuses like a STEAM Project pack, our Science Project Pack is what you need! Over 300+ Pages!

• 90+ classic science activities  with journal pages, supply lists, set up and process, and science information.  NEW! Activity-specific observation pages!
• Best science practices posters  and our original science method process folders for extra alternatives!
• Be a Collector activities pack  introduces kids to the world of making collections through the eyes of a scientist. What will they collect first?
• Know the Words Science vocabulary pack  includes flashcards, crosswords, and word searches that illuminate keywords in the experiments!
• My science journal writing prompts  explore what it means to be a scientist!!
• Bonus STEAM Project Pack:  Art meets science with doable projects!
• Bonus Quick Grab Packs for Biology, Earth Science, Chemistry, and Physics

Subscribe to receive a free 5-Day STEM Challenge Guide

~ projects to try now ~.

• ScHOOL Sign Up
• Scientist Sign Up
• Our Scientists
• Our Research
• Give us Feedback!
• In the News
• Fermentation, or how to blow up a balloon with yeast!

image bt Ingenza Ltd

If you have ever baked bread, you probably have encountered yeast and used it to make the dough rise. But how does it work? The yeast you can buy in a shop is called Saccharomyces cerevisiae , or just baker’s yeast. Yeasts break down sugars and produce alcohol, which is used in alcoholic beverages, and carbon dioxide, which is a gas that makes bread dough rise.

You can see the fermentation process in a very easy way at home, by mixing some active dry yeast, sugar and warm water in an empty bottle and fit a balloon over the bottle top. Watch the balloon blow up magically!

Here is how you can do it: 

• Packet of yeast
• Empty Water Bottle
• Funnel 

Use the funnel  to put a couple of spoonfuls of sugar in an empty water bottle. 

Fill half of the bottle with warm water.

Add a package of yeast. Yeast is activated when it gets wet. So, put the top on and shake the bottle. Open the bottle again and place the ballon over the bottle opening. 

Finally you wait for the magic to happen. It will take more than an hour to get the balloon really good and inflated.

But how does this work? Yeast  is a microscopic fungus. As the yeast eats the sugar, it releases a gas called carbon dioxide. The gas fills the bottle and then fills the balloon as more gas is created.

Tips for the experiment and food for thought:

• Try to use clear bottles, so you can see the liquid bubbling!
• Try repeating the experiment with cold water. Or, putting the bottles in a warm place like a sunny window sill. Does the temperature influence the activity of the yeast?
• Try adding different amounts of sugar (or no sugar!) to the mixture. Which bottles grow the balloon most?
• Can yeast use other sugars than sucrose (which is the sugar in household sugar)? How about using some fruit juice (with a lot of fructose) or milk (with lactose)?
• When the balloons are all blown up, don’t forget to take a whiff before throwing it away! What does the smell remind you of? How do different bottles differ in their smell?

If you want to see a video with the experiment click here . 

The same process happens when we are making bread. Check this video to find out more.

By Daniel Sachs

•     [email protected]

Sugar & Yeast Balloon Experiment

By: Author Sara McClure

Posted on Published: February 5, 2018  - Last updated: May 31, 2018

Categories Homeschool , Kids Activities , Science

Sharing is caring!

Did you know that you can blow up a balloon without using your mouth or a helium tank? You totally can. This super fun Sugar & Yeast Balloon Experiment will have kids wondering how it works. Much like our magic light bulb balloon experiment , this balloon experiment is easy to do. This is one of those experiments where the kids can do most if not all of the work. The only thing they might need help with is putting the balloon over the bottle opening. Everything else is easy-peasy. This is a great preschool or kindergarten science experiment and would even be a good balloon science fair project.

*Affiliate links are present.*

• Packet of yeast (We used Rapid Rise Yeast, but it doesn't matter.)
• Empty Water Bottle

How To Blow Up a Balloon with Yeast

For the yeast balloon experiment, put a couple of spoonfuls of sugar in the bottom of the empty water bottle . You can use the funnel to make this a little easier.

Fill the bottle  about half full with warm water.

Add a package of yeast .

Swirl the bottle  around or put the top on and shake the bottle to get the yeast wet to activate it.

Place the balloon over the bottle opening.

Now you wait for the magic to happen. This will take a while. I'd say we left ours for over an hour to let our balloon get really good and inflated.

It will slowly get bigger...

and bigger...

How does the yeast balloon experiment work?

Yeast is a microscopic fungus. As the yeast eats the sugar , it releases a gas called carbon dioxide. The gas fills the bottle and then fills the balloon as more gas is created.

More fun science experiments for kids you might like:

Moon Crater Experiment Simple Science: Observing Worms Simple Science: How to Make a Volcano with Kids Balloon Rocket STEM Activity

100 Screen-free Summer Activities for Kids | Happy Brown House

Thursday 31st of May 2018

[…] 26. Blow up a balloon with sugar and yeast […]

Vinegar and Baking Soda Balloon Experiment | Happy Brown House

Monday 12th of February 2018

[…] excitement. Trust me, they’ll want to do this experiment over and over again! Much like our Yeast Balloon Science Experiment, kids will learn how to blow up a balloon with vinegar and baking soda and learn a little chemistry […]

Amazingly Cool Classic Science | Yeast Science Experiment

Every kid should do at least several classic science experiments before they get too old to enjoy them. On the list today was the classic yeast science experiment. We decided to find out what type of sugar helped yeast grow best, or if sugar helps at all.

* This post may contain affiliate links for your convenience. Click here for my full disclosure.

We are on a small kick to explore foods that we eat at a Thanksgiving Feast and of course, bread is a very popular item. When the kids saw the dough rising in the bowl, they immediately had questions that they wanted answers to. That’s when I thought this would be the perfect way to explain the way yeast works.

Classic Yeast Science Experiment

What you’ll need for the yeast science experiment:.

• 3 types of sugar (we used brown sugar, white sugar, and honey)

I set everything up in advance of this project so the kids could jump right in. I measured 2 teaspoons of each type of sugar into four mini containers (we used film canisters) and laid everything out on the table for the kids to use.

The kids poured half a packet of yeast into each bottle, then added two teaspoons of warm water.

The kids next added one type of sugar to three bottles, but nothing to the last bottle. We labeled each bottle to keep track of what sugar was wear.

A little shake mixed up the bottles and we could already see the yeast starting to grow!

The kids screwed the caps back on the bottles and taped a water balloon to the top of each bottle spout (we had blown them up previously to stretch them out and make them easier to expand).

We set the bottles of yeast aside for 30 minutes, then came back to check our results.

Although it looked like the brown sugar activated the yeast the fastest, over the 30-minute period the white sugar outpaced it. The honey eventually blew up the balloon, but it took about an hour. The nothing jar never had enough air to blow up its balloon.

We were curious, so we put our yeast bottles into the bathtub and left it for several hours. That night, we looked at our bottles again. The white sugar bottle had enough pressure to pop the balloon off the top. The honey and brown sugar bottles had balloons almost completely filled with yeast. The no-sugar bottle was still sad and deflated.

The kids determined that if we wanted to make fluffy bread, we definitely should feed our yeast white sugar.

Looking for more STEAM (Science, Technology, Engineering, Arts and Math) projects and inspiration?

Check out my new book STEAM Kids Christmas and get a FREE STEAM Kids Coloring book  if you buy during launch week! You can get both books (eBook PDF format) for only $9.99! But the sale and bonus book offer ends November 21 , so grab your copy now and don’t miss out!

Get more information on STEAM Kids Christmas by clicking here . Or go order your copy now! eBook PDF or Paperback  

You can also get a bundle with our best selling STEAM Kids book, STEAM Christmas and STEAM Kids Coloring book for one low price: Click here to get your bundle today !

Not quite ready to jump in, don’t worry… you can hop over and grab a FREE Preview which includes 2 sample activities, 6 sample challenge cards, and the table of contents of the book! 

For more adventures in STEM Learning, check out:

FREE DOWNLOAD

Discover how to get siblings to get along even when all they do is annoy each other with the Sibling “Get Along” Poster Pack!

1 thought on “Amazingly Cool Classic Science | Yeast Science Experiment”

Pingback: The Coolest Science Fair Projects for Kids - Left Brain Craft Brain

Leave a Comment Cancel Reply

Your email address will not be published. Required fields are marked *

Save my name, email, and website in this browser for the next time I comment.

CONNECT WITH ME