Why do papadums puff and blister when roasted? Doing a demo for elementary kids and I know they will ask.
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I think the puffing has something to do with the water in the dough turning to steam, and it therefore creates a balloon effect.
It may also be the baking soda used in the papadum dough - often this is one of the ingredients.
I have looked at 10 papadum recipes; none used baking soda, and they are dried in the oven until crisp, very little to no moisture. Is there something about the flour that makes them blister?