The Poori Mystery

Why does a poori puff up when it is fried in oil ?

A poori is made out of  wheat flour (maida). Maida is mixed with water . The mixture is called dough. The dough is spread into a thin layer over a hard surface by using a roller.  Then the thin layer is gently dropped in very hot oil .

Maida spread with the wooden roller

Yummy pooris.

The actual story begins now . The outermost layer of the dough gets very hot and looses all its moisture. That is the reason you see the bubbles sprouting from the maida. A few milliseconds later the heat starts to pass through the inner layer layers by conduction. Now the moisture inside the inner layer starts to rapidly evaporate due to the high temperature and the steam generated tries to escape but all the steam cant escape from the poori so it starts to exert pressure on the poori from the inside which results in the swelling. After swelling the poori retains its swelled shape without collapsing due to the crispy skin. If u poke the poori when it is hot it will collapse as well as the steam will burn your finger :) .

Wont believe me???? Try it for yourself

Also try making a poori by making a small cut or a hole at the center of the maida. It wont swell.

PS : When water turns into steam,its volume increases to 1600 times the original volume. That is 1 liter bottle of pure water will occupy 1600 1 liter bottles when it becomes steam.

DISCLAIMER : All that I wrote in this post is what I think. I might be wrong too. But Im pretty sure that Im right. I will be glad if someone corrects me or proves that Im wrong. Im open to discussion.