This term in Science we are looking at Micro Organisms. We begun our Inquiry last week by Tuning In to what we already knew. Amongst many other things, we established that ONE type of Micro Organism is Yeast. This week we are Finding Out about yeast by comparing the making of bread with and without it. To begin with, we made two batches of bread dough that were exactly the same, except that one had no yeast added at all. When we poured them onto baking trays, we observed that they both looked pretty similar:

To observe the difference between them over time, we drew a red line around the two doughs, so that we could see any changes in ‘blob size’. After 45 minutes, we observed that both blobs had overlapped the red line in parts, but the Yeast Blob had expanded further. It was also higher.

Crossing over the red lines!

The Yeast Dough was higher and wider.

As the difference was not enourmous though, we did a bot of research and discovered that yeast thrives with heat. So (not entirely illogically) we decided to put a little bit of each dough into extreme heat (the oven) to see if that would cause a bigger difference between the two.

This finally gave us a clear distinction between the two doughs – the dough with Yeast rose much higher and was certainly much tastier!

The one on the left was much tastier, and yeastier.