Gluten is a protein in wheat flour and some other grains. It is the gluten in the flour that gets nice and stretchy when you add flour and knead it into a nice ball.
Experiment:Note: double up quantities if you prefer. The listed amounts are small so everyone could make their own. I did not try this with the class. My daughter likes to play with "bench flour" when I'm done shaping bread, but has trouble working it through the "sticky" phase and into the "smooth ball" consistency. It would probably be messy for preschoolers.
- small bowl
- 1/8 cup flour
- 2 1/4 tsp water, plus more as required
- Put the flour and water in a bowl. Mix them together with your fingers.
- Knead the dough as it balls up, adding small amounts of water or flour, if necessary to form a nicely textured dough ball
- Keep mixing, rolling, and mashing until it turns into a springy ball.
- Flatten the ball out, and gently stretch it like pizza dough. Does it remind you of a balloon? Can you shape it into a bubble? Try blowing it like bubble gum, but with it on the outside of your lips. Then, seal off a bubble by pinching the dough together. Of course, now you'll have to pop it!
- Flour kneaded with water creates a springy, stretchy dough.
- Dough can capture air bubbles.
- When coupled with the yeast experiment, you find that: Yeast produces gas. Dough can trap gas bubbles. When mixed into the dough, the yeast will make thousands of tiny bubbles in the dough. This is how yeast breads rise. Baking "freezes" the bubbles, which are visible if you look closely at a slice of bread.
- Kneaded dough becomes stretchy because the gluten molecules in flour link into long, stringy "rubber bands".
- Careful rincing of a really well-kneaded ball will leave you with a ball of gluten only. However, this is tricky and messy, and I did not find that it really adds anything to the class.
- Gluten is great for bread, giving it rise and bite.
- Gluten is bad for cookies and cakes, making them tough and hard, and preventing "snap" and "crumble".
- Fats interfere with gluten development. Working fats into flour before adding the water will help make more tender pastries and biscuits, but is bad for bread.