On Food and Cooking

toward its original shape when the pressure is
removed. Thanks to this combination of
properties, wheat dough can expand to
incorporate the carbon dioxide gas produced
by yeast, and yet resists enough that its bubble
walls won’t thin to the breaking point.
Gluten plasticity results from the presence
of the gliadin proteins among the glutenins;
because they’re compact, the gliadins act
something like ball bearings, allowing
portions of the glutenins to slide past each
other without bonding. Elasticity results from
the kinked and coiled structure of the
interconnected gluten proteins. Kneading
unfolds and aligns the protein molecules, but
there are still loops and kinks along their
lengths. Stretching the dough straightens out
these loops and kinks, but when the pressure
is relieved, the molecules tend to revert to
their original kinkiness. In addition, the coiled
spring-like structure of individual proteins
can extend and store some of the energy of