On Food and Cooking

Fizzy   and Crackling   Candies

Candies that fizz and crackle in the mouth
were developed in the 19th century by
embedding the equivalent of baking
powder in a very low-moisture sugar syrup
as it cools and hardens. Remember that
baking powder is a mixture of an acid
together with alkaline baking soda. When
the two components are moistened together
in a batter, they react to produce carbon
dioxide gas. Similarly, when the dry
crystals of citric or malic acid and sodium
bicarbonate in a candy are moistened
together in the mouth, they react and form
bubbles of carbon dioxide that provide the
sensation of tartness and prickly
foaminess.
A 20th-century industrial twist on this
idea produced Pop or Space Rocks, which
instantly burst and then disappear in the
mouth. A scientist at General Foods found
that he could supercharge a concentrated