get tangled up and slow the motion of other molecules and granules in the vicinity A small number of very long amylose molecules, then, will the job of more but shorter amylose molecules, and of many more bushy amylopectins For this reason, the cook can obtain the same degree of thickening from a smaller amount of long-amylose potato starch than from moderate-amylose wheat and corn starches Two kinds of starch Starch molecules are chains made up of hundreds or thousands of glucose molecules bonded together They take two forms: straight chains of amylose (left), and branched chains of amylopectin (right) A long amylose chain moves around in a larger volume than the more compact amylopectin containing the same number of glucose molecules, and is more likely to tangle with other chains Amylose is therefore a more effective thickener than amylopectin Pure Starch Starch has been separated from the proteins and other materials in grains since ancient times The Romans called it amylum, which meant “not ground at the mill.” They made it by grinding wheat in a mortar and then soaking the flour for days, during which bacteria grew and digested the grain’s cell walls and gluten proteins while leaving the dense, solid starch grains intact They reground the dregs, and then pressed them through fine linen, which retained the small grains The starch grains were dried in the sun, and then either cooked in milk or used to thicken sauces ... while leaving the dense, solid starch grains intact They reground the dregs, and then pressed them through fine linen, which retained the small grains The starch grains were dried in the sun, and then either cooked in milk... at the mill.” They made it by grinding wheat in a mortar and then soaking the flour for days, during which bacteria grew and digested the grain’s cell walls and gluten proteins while leaving the dense, solid starch grains...long amylose chain moves around in a larger volume than the more compact amylopectin containing the same number of glucose molecules, and is more likely to tangle with other chains