Lab: How and why does Bread rise? Part 1

03/02/15

Today I started making bread. The question I'm asking and answering is, How/why does bread rise?

Ingredients
1/2 pound of white flour
1/2 pound of wheat flour
1 cup of warm water
1/2 cup of milk
1 tablespoon of sugar
1 tablespoon of salt
1/4 ounce bag of yeast

I mixed these ingredients together and let it sit for 1 hour and 30 minutes. It grew twice as much as it was before due to the yeast reaction. After the time is up, I had to heat up the oven to 445 F. Then in 30 minutes I had to bake the bread covered, and 10 minutes uncovered.

What is yeast?

The yeast is actually a living. It's a fungus, which makes it similar to mushrooms and mold. The chemical composition yeast has is: Water 73% - 75%, Protein 13%,   Minor amounts of minerals (Potassium, calcium, sodium, magnesium, phosphorus), fat, carbohydrate, vitamins (B, E) and enzymes.

What happens to the yeast?

In 1859, Louis Pasteur, the father of modern microbiology, discovered how yeast works. If the yeast comes in contact with warm water, it comes to life. When it's exposed to sugar, which is in the bread and in flour, it begins to eat, and digests the portions of the sugar. The yeast eats in only a short period of time, and eventually will die within a few hours. Especially when the dough is allowed to cool off or exposed to too much air.