sodium hydroxide (lye) or sodium carbonate.
The heat and moisture combine to gelate the
surface starch. The dough is then salted and
baked for about five minutes in a very hot
oven. The starch gel hardens to a shiny finish
and thanks to the alkaline conditions created
by the lye, browning-reaction pigments and
flavor compounds rapidly accumulate. (The
lye reacts with carbon dioxide in the oven to
form a harmless edible carbonate.) The final
step is a long, slow bake to dry the whole
pretzel out. The pretzel is crisp but fragile
thanks to tiny airy bubbles and ungelated
starch granules throughout, and it has a
distinctive flavor from its alkaline-browned
surface.
Soft and homemade pretzels may be
allowed to rise before being boiled briefly in a
solution of baking soda and then baked for 10
or 15 minutes in a hot oven.
Bagels The bagel is a relatively small, ring-