Bread dough rises because of yeast. Yeast is a fungus made of a single cell, and the yeast in bread dough is alive. Dry yeast needs warm water to wake up. Yeast eats sugar. It gives off a gas called carbon dioxide. Yeast gives off a second product as it eats sugar: an alcohol called ethanol.
Children need a grown-up with them in the kitchen when they bake. Dough rises best in a warm place, above 75 degrees Fahrenheit. Bread dough is set in a warm place to rise until it doubles in size. Rising dough is covered, often with a clean, damp towel. Salt slows down yeast, and yeast dies when it gets too hot.
Kneading means pushing, pulling and stretching the dough. Kneading makes the gluten in dough stretchy. Gluten works like a net that traps the gas in dough. Proofing is a rest time for the dough, and during that time the yeast makes gas in the dough. Punching down risen dough means pressing out some of the air with your fist.
A dough left to rise too long is over-fermented. The gas cells can burst so the loaf falls, and the bread can turn out hard and tough. When dough first goes into a hot oven it rises fast, which bakers call oven spring. Water in dough turns to steam in the oven, and the steam pushes the dough up.
Baking soda and baking powder make gas bubbles that help cakes and pancakes rise. Baking powder has an acid already mixed in with the baking soda. Baking soda starts to make gas almost as soon as it touches an acid. Fat in dough makes baked goods tender. A chemical reaction makes the crust of bread dark and toasty. Bread is done baking when it turns golden brown.
Words to know
- yeast: a living fungus
- gluten: dough net
- ethanol: an alcohol
- proofing: rest time
The short version
Yeast is a living fungus that eats sugar and gives off carbon dioxide gas. Gluten works like a net that traps the gas in dough, and dough set in a warm place rises until it doubles in size. In a hot oven it rises fast, which bakers call oven spring, and steam pushes the dough up.
Quick facts
- Yeast is alive. It is a fungus made of a single cell.
- Yeast gives off carbon dioxide and a second product, an alcohol called ethanol.
- Dough rises best in a warm place, above 75 degrees Fahrenheit.
- Water in dough turns to steam in the oven, and the steam pushes the dough up.
Why does bread rise?
Yeast helps bread dough rise. Yeast eats sugar and gives off a gas called carbon dioxide. Gluten works like a net that traps the gas in dough, so the dough rises until it doubles in size in a warm place.
What is the difference between baking soda and baking powder?
Baking powder has an acid already mixed in with the baking soda. Baking soda starts to make gas almost as soon as it touches an acid. Both make carbon dioxide gas bubbles that help cakes and pancakes rise.
