Yeasty beasties

Thanks to http://www.exploratorium.edu/
cooking/bread/activity-yeast.html

for the idea.

and

http://www.sciencebuddies.org/
science-fair-projects/project_ideas/MicroBio_p011.shtml

for the title


We will explore other permutations [glucose, maltose, very dilute NaCl, flour, flour plus malted barley flour] in class to see what is fastest.

Pink balloon;
water 250 ml ~ 36 deg C
1 packet [15 g] Fleischmann's fresh compressed yeast
10 g sucrose

Green balloon;
same as above plus 6 g NaCl to slow yeast activity


Time zero
Time 45 mins at room temp
Time 90 min at room temp
Clearly the concentration of salt has slowed the rate and amount of gas production in the green balloon.