Why is salt added to yeast dough?

The answer

Salt is added to yeast dough for three reasons: it improves flavor, it strengthens the gluten, and it moderates fermentation so the dough does not race ahead. Dough made without salt tends to taste flat, feel slack and ferment unevenly. Too much salt, or yeast sitting in direct contact with a pile of it, slows or harms the cells, so measure carefully and mix the salt through the flour. Many bread recipes use a small percentage of the flour weight, so follow the recipe's amount.