Is there a way to incorporate air into a gel made from starch and will the pockets of air stay when dehydrated? I'm experimenting with creating puff cereal at home. I was wondering if creating a gel, dehydrating it and then puffing it in an oven with high pressure is the only way. I actually had an successfull experiment with making a puff cereal mix mainly made of cooked starch, dehydrating it and then putting the dehydrated balls into the microwave. The remaining moisture made the balls puff into puff cereal and it actually worked quite well. This is a technique used for shrimp crackers as well. Now here is the catch. It works well, but only with a few balls at a time (one ball works best). This is due to the uneven distribution of radiation which causes some balls to puff quickly and others to take forever, while the other ones burn. So I'm thinking about other ways to incorporate air into the gel without using something like egg whites which would change the texture of the final product. The goal is to avoid the uneven cooking of a microwave oven while also avoiding the need for a professional puffing gun or extruder.
You can create a &quot;puffed&quot; texture with methylcellulose.  Chef Jose Andres made a popular dish, based on this concept, at one of his restaurants, using beetroot.  Methylcellulose is whipped into the base, and it foams like whipped egg white.  Then you can pipe the mixture onto a dehydrator tray and dehydrate.  There is no need to bake or cook after that.  I am not sure how well it will work as a cereal. It might not hold up well in the presence of milk.
It is also possible to puff many grains simply by overcooking (to gelatanize the starch), dehydrating, and deep frying.