On Food and Cooking

of chains of individual molecules of the sugar
called glucose (p. 804). But there are two
different kinds of starch molecules in starch
granules, and they behave very differently.
Amylose molecules are made from around
1,000 glucose sugars, and are mainly one
extended chain, with just a few long branches.
Amylopectin molecules are made from 5,000
to 20,000 sugars and have hundreds of short
branches. Amylose is thus a relatively small,
simple molecule that can easily settle into
compact, orderly, tightly bonded clusters,
while amylopectin is a large, bushy, bulky
molecule that doesn’t cluster easily or tightly.
Both amylose and amylopectin are packed
together in the raw starch granule, in
proportions that depend on the kind and
variety of seed. Legume starch granules are
30% or more amylose, and wheat, barley,
maize, and long-grain rice granules are around
20%. Short-grain rice granules contain about
15% amylose, while “sticky” rice starch