Why does a Chapatti Bulge on Baking?

            You might have often noticed that when your mother bakes chapattis on a gas stove, it puffs up. Let us understand the reason for this swelling.

            To prepare the dough of chapattis, flour is mixed with water. It is forming this dough that the chapattis are made. First of all, the chapatti is baked on both sides on a tawa or griddle. It is then put directly on the flame of the gas stove.

Chapati Buging

            The portion in touch with the flame gets heated up. This heat produces water vapor as steam and carbon dioxide inside the chapatti. This steam and carbon dioxide try to escape, being under pressure, and make the chapatti bulge.

            If there is a hole anywhere in the chapatti, this gas and steam escapes out, and the chapatti does not bulge. A similar phenomenon takes place when puris are fried in a kadahi in vegetable oil or other frying medium.