What Makes Sticky Rice Sticky?
The Food Scientist answers vexing food questions
What is sticky rice?
Sticky rice — also known as glutinous rice — is a short-grain, Asian varietal that is used in many cuisines for its characteristic sticky texture. Don’t let the name confuse you though, since glutinous rice contains no gluten — a protein composite found in wheat — making it edible for anyone with gluten allergies or sensitivities such as celiac disease.
What makes it sticky?
Unlike some foods such as root vegetables, which contain the two starch components amylose and amylopectin, glutinous rice only contains one: amylopectin; there is actually a very small percentage of amylose in glutinous rice, but the amount is negligible and won’t be considered in this explanation. So how do those inedible, uncooked grains turn into the deliciously sticky situation (in a good way) with which you are familiar?
Being the more water-soluble of the two starches, amylopectin — when added to hot water — begins to break apart. I stress hot water because this process is entirely heat-dependent, meaning that if you simply dumped uncooked rice into a pot of cold water, nothing would happen. It’s only when the conditions are right that the rice starch molecules can break apart, causing the structure of the grain to become soft, mushy and sticky. Just the way we like it.
Fortunately, starch isn’t only good at making rice easier to eat with chopsticks and tastier to eat when soaked with Thai spices. There are countless other uses for starch and its glue-like qualities, both in and out of the kitchen. Without starch products derived from foods like wheat, rice and vegetables, the collars on your favorite dress shirts would be sad and limp. Wallpaper and most glue as we know it would cease to work. Then where would we be?