In
baking, a
crust is the outer, hard skin of
bread or the shell of a
pie. Generally, it is made up of at least
shortening or another
fat,
water,
flour, and
salt. It may also include
milk,
sugar, or other ingredients that contribute to the taste or texture. An
egg or
milk wash can be used to decorate the outside, as well as coarse
sugar. A good crust contributes to a delicious pastry.