The initial clarification of cane and beet
juice is now accomplished without eggs or
blood; heat and lime are generally used to
coagulate and remove proteins and other
impurities. Rather than waiting for gravity
to draw off molasses, refiners use centrifuges,
which spin the raw sugar as a
salad spinner spins greens, forcing the liquid
off the crystals in minutes rather than
weeks. The sucrose is whitened by the technique
of decolorization, in which granular
carbon—a material like activated charcoal
that can absorb undesirable molecules on
its large surface area—is added to the centrifuged,
redissolved sugar. After it absorbs
the last remaining impurities, the charcoal
is filtered out. The final crystallization
process is carefully controlled to give individual
sugar crystals of uniform size. Our
table sugar is an astonishingly pure 99.85%
sucrose.