How is the yeast in bread process stopped?

There are a couple ways the yeast in bread can be stopped from reproducing and fermenting.

1) Temperature: Yeast are living organisms, and most living organisms require a certain temperature range to survive. If the temperature of the bread dough gets too high, the yeast will die. If the bread is placed in the refrigerator, then the yeast will go into a dormant state and stop reproducing. Once taken out and placed in a warmer environment, they will start reproducing again.

2) pH level: Yeast are most active in a neutral pH environment. By changing the pH level of the dough, the fermentation process of the yeast can be altered. Acidic ingredients such as vinegar or lemon juice can lower the pH level of the dough and slow down or stop the yeast's activity.

3) Salt Concentration: Salt can alter the chemical environment in dough, affecting yeast activity. A high concentration of salt can limit the water available for yeast growth, thereby slowing down or preventing fermentation.

When bread is baking in an oven, the yeast will eventually die due to the high temperatures. This is why oven-baked bread does not continue to rise after it has come out of the oven.