Life Cycle of Bread & Science Experiments for Kids

Kneading Bread

• Kneading bread causes the proteins in the flour to develop into elastic sheets of gluten. This chemical process leads to changes in the look and feel of bread dough that children can observe as they knead dough. Make a batch of dough and let each child knead a small lump, or let them watch as you knead it. Help children observe how the dough changes, noting the smoother surface and increased stretchiness. Explain that the stretchy gluten holds in bubbles to help the bread rise better.

Starch and Gluten

• For a more dramatic demonstration of the properties of bread gluten, knead a lump of dough thoroughly and then soak it in cold water for about half an hour. Let children observe the water, which should be cloudy because of the starch that soaked out of the dough lump. Dump the starchy water and replace it with clean water, then continue gently kneading the dough underwater, replacing the water whenever it gets cloudy. When no more starch comes out, the dough will be made almost entirely of gluten. Children can touch and stretch the spongy mass as you explain that this helps bread dough rise.

Living Yeast

• Seeing bread rise is a visually dramatic result of a microscopic chemical reaction. Explain to children that yeast is actually a tiny living thing that grows and breathes when we feed it with the sugars found in flour. Let children watch you put the yeast into the dough, then let it rise and come back later to observe the effects of the yeast. There should be bubbles throughout the dough that form as the yeast multiplies, spreads through the dough and expels carbon dioxide.

Bread Mold

• Bread mold is another tiny organism that feeds on the nutrients in bread and multiplies visibly. Leave a slice of old bread out until it begins to grow mold, then observe the colors and size of the mold colony as it grows over a few days. Older children may want to experiment with the effects of environmental changes on mold growth. For example, they can measure how the rate of mold growth differs on different kinds of bread or at different temperatures.