What exactly is a Rice Krispy? What are its ingredients and how is it made?

Rice Krispies belong to the category of puffed grain cereals, which commonly includes rice, wheat, and corn. Other puffed cereals, like Trix, Kix, Cheerios, and Cocoa Puffs, also exist, and puffing is a popular technique in the breakfast cereal industry!

To make Rice Krispies, rice is popped in a way that's similar to popping popcorn. As you might know from reading about how popcorn works, three things are required for popping: moisture inside the kernel, starch inside the kernel, and a hard shell to hold in the pressure. Rice lacks moisture, but by steaming it to add enough moisture to the kernel, the rice can be oven-popped or oil-popped. While not as dramatic as popcorn, the process is the same. Rice Krispies are oven-popped, creating the perfect texture for that satisfying "snap! crackle! pop!" when milk is poured on.

A widely used method for puffing rice (like in Quaker Puffed Rice), corn (like in Sugar Pops), or wheat (like in Sugar Smacks) is called gun puffing. This involves cooking and conditioning the grain to perfect the moisture content, then pressurizing it to about 200 PSI. The pressure is released quickly, causing the kernel to puff due to the stored pressure. If you've ever heard about "shooting the cereal out of a gun" in ads, this is what they mean! The puffing process makes the rice spongy, not crispy.

For puffed dough, small dough balls can be created and hot-air popped. When heated quickly, the moisture in the dough causes it to flash boil and puff up. A cereal like Cap'n Crunch undergoes an extrusion process, where the dough is cooked, cut, pressurized, puffed, and dried continuously. This explains the squeezed appearance at the ends of each piece.