Hameds Science

PROBLEM

How does the temperature of the yeast affect the rising of bread?

HYPOTHESIS

The bread with the warm water will rise (NOTE* the water should not be very hot nor very cold but it should be warm for the bread to rise)

Introduction

The purpose of this experiment is to discover the effect of temperature upon the rising of bread dough. The process of dough rising is based on yeast. Yeast is a type of fungus which breaks sugar down into smaller components. The type of yeast used for these tests is Saccharomyces cerevisiae, which was domesticated for wine, beer and bread production thousands of years ago. S. cerevisiae is commonly referred to as baker’s yeast or brewer’s yeast for this reason. Yeasts used for leavening bread can be either caught from the environment or produced commercially. In the environment, yeast can easily be found in fruits and berries (such as apples, peaches, and grapes), as well as in plant exudates (such as sap).When mixed with bread dough, the yeast converts sugar molecules into carbon dioxide (CO2), alcohol and water. The CO2 expands in the dough to produce gaseous bubbles. These bubbles cause the bread to rise - the more CO2 present, the faster the bread will rise. If temperature is related to the amount of CO2 produced by yeast, then higher temperatures will result in increased production of CO2.

Experiment

Materials required

* 3 1/2 cups of flour

* 1 3/4 table spoons of dry yeast

* 1 1/4 cups of water

* 1/4 cups of sugar

* 1/4 cups of shortening

* 1 table spoon of salt

Steps

1. Add yeast to water

2. Mix other ingredients to bowl

3. Gradually add the yeast and water to mixture

4. Shape materials into loaf like

DATA

BEFORELoaf of breadTemperature of water for yeast

Boiling |

Room temperature 37 degrees |

Ice water |

| AFTERAppearance of bread

Heavy , doesn't look fully cooked |

Came out as normal bread |

Looks like stale bread |

Loaf of bread |...