Expert: Walter Hintz - 3/26/2008

Question
MY DAUGHTER IS IN 4TH GRADE AND HAS A SCIENCE FAIT PROJECT! HER PROJECT IS TO DETERMINE IF DIFFERENT KINDS OF SUGARS AFFECTS YEASTS ABILTY TO GROW! I AM NOT QUITE SURE HOW TO SET UP THIS EXPERIMENT, PLEASE HELP! THANKS

Answer
Hi kim
This is an ambitious project for a 4th grader.  What you have to measure is the rate at which yeasts ferment sugar which is what they do.  The rate of fermentation can be observed by seeing how much Carbon dioxide is formed. The greater the rate the greater the CO2.  This can be easily done by adding yeast and sugar to small plastic baggies, tieing them shut and keeping them warm.  he fermentation occurs very quickly and bubbles of gas form.  They can be compared by noticing the amount of bubbles.
 The problem may arise in getting different sugars.  You can use table sugar (sucrose) and go to the drug store and but glucose tabs where they sell diabetic supplies.  Health food stores may have fructose or maltose. Try using a sugar substitute also just to show the difference.
 There is something you must also do.  Scientific tests require controls so be sure you use equal amounts of sugars and water in every bag.  If you need more help let me know.
 Be sure you tell how to set it up and let her do it.  Do not do it for her.