Baked cereals follow in the mold of the
19th century original, C. W. Post’s Grape
Nuts: dough of some sort is formed,
baked, sometimes granulated and
rebaked.
Extruded cereals, usually small crunchy
shapes, are made from doughs that are
forced at high pressure through small
openings, much as dried pastas are made.
The pressure and friction generate high
temperatures that cook the dough as it’s
shaped, and the pressure drop as the
formed dough exits the extruder can
cause it to expand as well.Grains are still the base for these cereals,
but they may actually be outweighed by sugar
and other sweeteners. Sucrose is especially
favored for its ability to give a frosty or
glassy surface to the crisp grain flakes and
slow the penetration of milk and resulting
sogginess.