Bread in a Bag

Instructions

  • In a resealable bag, combine 1 cup flour, 3 tablespoons sugar, 1 packet yeast, and 1 cup warm water. Remove air, seal, and mix until uniform. Let rest for 10 minutes until bubbles form.

  • In a small bowl, mix 1 cup flour, olive oil, and salt. Add to the bag, remove air, seal, and mix well.

  • Add another cup of flour to the bag, mixing until no flour pockets remain.

  • Remove from bag. Knead the dough on a floured surface for 8-10 minutes until smooth. Divide into greased pans or shape as desired. Cover and let rise for 45-60 minutes until doubled.

  • Bake at 375°F for 25 minutes or until golden brown.

Observations:

  • When the dough grows in size, carbon dioxide gas is creating tiny bubbles. As these bubbles form and expand within the dough, they cause it to rise.

Materials

  • 1 large freezer zipper bag

  • 3 cups flour separated

  • 1 0.25 oz. packet rapid rise yeast

  • 1 cup warm water

  • 3 Tablespoons white sugar

  • 3 Tablespoons olive oil

  • 1 1/2 teaspoon salt

  • Butter or non-stick spray for greasing pans

  • 2 mini loaf pans

Questions:

  • What is yeast?

  • Why does the bag puff up?

  • What role does sugar play in the experiment?

  • Why is it important to use warm water vs cold or hot?

What is happening?

The science behind "bread in a bag" involves a chemical reaction where yeast produces carbon dioxide gas, causing the dough to rise. When the yeast (a microorganism) is fed sugar and warm water, it undergoes fermentation, releasing carbon dioxide bubbles that get trapped by the gluten in the flour, creating the dough's structure and airy texture. The bag is used as a mixing vessel to contain the ingredients and observe this process.