Or for that matter, how do you get flakes from Bran?
How did flakes and O’s become the dominant players in the cereal shape market, anyhow?
In the words of the immortal Gallagher, “you gotta crack those babies just right…”
Realistically? Grind it up, add water, spew the goop onto a surface where it can dry.
[Homer voice] Mmmmm. Spewed goop. [/Hv]
Read William Poundstone’s book Biggest Secrets (the third and last of the series, unless they come up with a degree greater than “superlative”). The chapter on Kellogg’s Suger Frosted Flakes tells in great detail how corn flakes are made. One flake per kernel of corn, BTW, which is why each flake is the size it is.
Kellogg, seeking to develop health foods for a sanitarium in Battle Creek, Michigan, first made wheat flakes by accident. The technique was transferred to corn, and the breakfast cereal industry was born.
http://www.kelloggs.ie/general/history2.html
Briefly, cook a grain into a mash (in the case of corn flakes, add malt for flavor), spread the mash out on a flat surface and let it dry, and then break it into flakes. Mmmm mmmm good. Oh wait; that’s soup.