On Food and Cooking

vegetable shortening — to make a sweet,
creamy, light mass. The sugar particles
must be small enough not to make the
frosting seem grainy, so fine grades of
powdered sugar are the usual choice.
Cooked frostings and icings include eggs
or flour and owe their body in part to the
egg proteins or flour starch. Because the
sugar dissolves during the cooking, its
particle size is unimportant.
Cooking the Syrup Raises the Sugar
Concentration As a sugar solution boils,
water molecules evaporate from the liquid
phase into the air, while the sugar molecules
stay behind. The sugar molecules therefore
account for a larger and larger proportion of
all the molecules in the solution. So as it
boils, the syrup gets more and more
concentrated: and this in turn causes its
boiling point to continue to rise. In order to
make a syrup of a given sugar concentration,
all the candy maker has to do is heat a mixture