chemistry science fair project (yogurt and yeast)

[bombae09]

the experiment is based upon this question: CAN YOGURT EFFECT YEAST GROTWH?
my issue is that i dont know what kind of yeast im supposed to use, is the variable yeast or yogurt, and with a project like this how long will it take( as in days) to determine such answers for such a question. i am thankful for any of the help i can get. im just lost on how to conduct my experiment

[JanelleSchlossberger]

Dear bombae09,

It sounds like you may want to first learn about yeast in general before designing your experiment. I believe that you have an interesting topic to work with and you just need to figure out what makes yeast special and what unique qualities it has. Afterwards you can then decide how to introduce the concept of using yogurt in your experiment and deciding what property about yeast you want to measure.

Here are some informative web sites to help you get started in your research:

http://www.lesaffreyeastcorp.com/SoY/experiments.html
http://www.accessexcellence.org/AE/AEC/ ... _food.html
http://www.horacemann.pvt.k12.ny.us/aca ... yeast.html

Good luck with your experiment
Janelle

[paulogoeb]

My personal opinion is that you should use a yeast known as Saccharomyces cerevisiae (http://en.wikipedia.org/wiki/Saccharomyces_cerevisiae). This is a common baking (for cakes and things like that) and brewing (wine) and is also fairly easy to culture. See if you can find information from your teacher/librarian on how to culture yeast, because they could probably direct you to a good source.
In this case, the explanatory variable (often graphed on the x-axis) is the yogurt, and the response variable (often graphed on the y-axis) id the yeast growth.
think you should monitor the yeast growth for at least 2-4 weeks.
Hope that helps...