what makes yeast grow? we did several experiments testing which ingredients make yeast grow best. we labeled 4 baggies as follows:
sugar + warm water
sugar + cold water
sugar + salt + warm water
no sugar + warm water
we added a package of yeast to each plastic bag, 2 tsp. of sugar to each of the bags that required sugar, and 1 tsp. of salt to the bag that said salt. afterwards we added 1/2 cup water to each baggie. we sealed the bags, squeezing out as much extra air as possible and let them sit.
a short while later we found some of the bags had puffed up! once again we made carbon dioxide! when growing yeast cells eat starch they make a gas (carbon dioxide) that form lots of tiny bubbles, which pop during baking- leaving tiny holes in the bread.
the kids recorded the results of their baggie experiment in their journals.