• Skip to primary navigation
  • Skip to main content
  • Skip to primary sidebar
Menu
  • Science Experiments For Kids
  • Science Fair Projects
  • Science Facts
  • Science Questions
  • About
    • Emma Vanstone
    • About Science Sparks
Science Experiments for Kids
Menu
  • STEM Challenges
    • STEM Challenges
    • FREE STEM Challenge Templates
  • Early Years Science
    • Preschool Science
    • Sensory and Messy Play
    • Understanding of the World
    • Pirate Science Experiments
  • Primary Science
    • Baking Soda Experiments
    • Candy Experiments
    • Biology
    • Climate Change for Kids
    • Coding for Kids
    • Chemistry
    • Electricity for Kids
    • Magic Science Experiments
    • Harry Potter Experiments
    • Human Body Science
    • Air Pressure Experiments
    • Life Cycles
    • LEGO Science Experiments
    • Kitchen Science
    • Famous Scientists
    • Forces and Motion
    • Science Sparks Snippets
    • Key Stage 1 Science
      • Animals
      • Everyday Materials
      • Plants
      • Coding Activities
      • Humans and Health
      • Fine Motor skills
      • Science and Literacy
    • Key Stage 2 Science
      • Animals, Including Humans
      • Electricity
      • Light
      • Plants
      • Materials and their Properties
  • Holiday Science
    • Christmas Science
    • Halloween Science
    • Easter Science
  • Storybook Themed Science Experiments
  • Wonderful Women in STEM
  • FREE Science Resources
menu icon
go to homepage
search icon
Homepage link
  • FREE Experiments
  • Science for Kids
    • Kitchen Science
    • Climate Change
    • Egg Experiments
    • Fairy Tale Science
    • Edible Science
    • Human Health
    • Chemistry
    • Inspirational Women
    • Forces and Motion
  • Science Fair Projects
  • STEM Challenges
  • Science Sparks Books
  • Contact Science Sparks
  • Science Resources for Home and School

×
Home » Science Experiments for Kids » Biology » What is Yeast?

What is Yeast?

Modified: Jun 16, 2021 · Published: Jan 21, 2012 by Emma Vanstone · This post may contain affiliate links · 4 Comments

Yeast is a living single celled organism commonly used in baking. Yeast is a type of leavener ( baking soda and baking powder can also be used as leavening agents ). Yeast converts sugar and starch ( from the sugar and flour in the bread mix ) into carbon dioxide and ethanol. The carbon dioxide gas makes the dough rise. Yeast works best in a warm, moist environment, which is why it’s best to leave the dough somewhere warm to rise. This conversion of sugar into carbon dioxide and ethanol is called anaerobic respiration.

We can see respiration occurring in yeast when we make bread or pizza dough.

Note – respiration in yeast is anaerobic respiration – this means it doesn’t use oxygen

Pizza Dough Respiration Investigation

Pizza dough ingredients

500g Strong White Flour

7g Yeast (Fast)

1tbsp caster sugar

330ml Luke warm water

1 tsp salt

1tbsp olive oil

How to make pizza dough

  • Mix the yeast, sugar and water in a jug and put to one side.
  • Sieve the flour into a mixing bowl and add a pinch of salt.
  • Gradually add the water until a nice elastic dough is formed.
  • Knead the dough well, strong flour will take a lot of effort to get nice and elastic, so work it hard.
Pizza dough being kneaded by a child's hands
Knead the pizza dough – image taken from Snackable Science
pizza dough before rising

Leave it somewhere warm, we left ours in the airing cupboard for about an hour. Look how much it increased in size.

Pizza dough risen
Pizza dough after rising

Once risen, knead the air out of the dough again and roll it out to make your pizza bases.

We turned our pizza into a plant cell model. The green peppers are chloroplasts!

Pizza Plant Cell Model #plantcellmodel
Pizza Plant Cell model

More Yeast Experiments

Did you know you can use the power of yeast to blow up a balloon? First blow up the balloon and let the air out. Pour a packet of yeast, warm water and a tablespoon of sugar into a small bottle and quickly pop the balloon on top. Give the mixture a shake and you should find the balloon blows up thanks to the carbon dioxide gas produced by the yeast.

Image if yeast bread and pizza for a respiration experiment
Yeast/Respiration Experiment for Kids

Last Updated on June 16, 2021 by Emma Vanstone

More Biology

  • Edible Butterfly Life cycle
    Edible Butterfly Life Cycle
  • image of a bug and green leaves as a cover image for a collection of biology experiments for kids
    Easy Biology Experiments for Kids
  • How do birds fly?
  • Transpiration flower - plant science for kids
    Transpiration Experiment – Colour Changing Flowers

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

Leave a Reply Cancel reply

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

Primary Sidebar

Welcome!

Imagine a world where science education is accessible to everyone and is all about hands-on, exciting discoveries. That’s the world I want to create.

More about me

Around the World in 50 Experiments

50 experiments about countries of the world

Footer

↑ back to top

Science Sparks - FREE science experiments for kids

Newsletter

  • Sign Up! for emails and updates

Contact

  • Contact
  • Privacy Policy
  • Services
  • Media Kit
  • FAQ

As an Amazon Associate, I earn from qualifying purchases.

Copyright © 2025 Science Sparks - Wild Sparks Enterprises Ltd