Dear Mr. Alice: My mom said you can answer my question. What makes Rice Krispies cereal make so much noise? — Jodie, age 6, San Diego
Hi, Jodie. That’s a pretty big question for a six-year-old, but I’ll do my best. First of all, each little brown Krispie in your cereal bowl started out as one tiny piece of uncooked white rice just about as hard as a rock. The Rice Krispie makers take big piles of rice and tumble it in a machine, kind of like your mom’s washing machine, only a lot bigger. This covers the rice with water that has salt, sugar, vitamins, minerals, and malt flavoring in it. Then the stuff goes into a big steam cooker, where the hard rice grains get all fat and soft. The rice comes out of the steamer kind of like your mom’s wet laundry, and it has to be dried off just a little bit so it’s not quite so mooshy. Once all the extra water is gone, the rice probably looks a lot like the rice your mom serves with that ooky Chinese food or with those yummy tacos.
Next, all the rice gets spread out on a long, long sheet of metal, kind of like a whole bunch of big cookie pans stuck together end to end. The sheet carries the soft rice between two metal rollers that smash each rice grain completely flat. It’s like when your mom irons your shorts to get the wrinkles out. Now all the rice pieces are wet and flat and white and don’t look much like what comes out of the box. It’s the next step that turns the rice into Krispies.
Once the rice has been squooshed flat by the rollers, it goes through a toasting oven that’s kind of like a big hair dryer that blows really hot air onto the rice. The hot air blows up the rice grains like little balloons and toasts them and turns them brown. And each little Krispie now has bubbles of air trapped inside it. When you pour on the milk, the liquid is sucked up into some parts of the toasty rice but not into others. The wet part of the Krispie gets fatter and changes shape and stretches the parts of the Krispie that are still dry (that’s mostly the part around the air bubbles). When the wet parts of the Krispie Finally pull hard enough, the dry parts snap open and make a noise loud enough for you to hear. Have you ever picked up a stick and bent it by pulling on the ends? If you bend it far enough, the stick finally snaps. That’s pretty much what happens in your cereal bowl.
You might notice that some other cereals make a little noise when you pour milk on them. But the Krispie people make sure they toast the rice in just the right way so the snaps and crackles and pops are good and loud. They’ve been making their cereal that way for almost 70 years. That’s ten times longer than you’ve been alive. It’s even longer than your mom’s been alive. Why, Rice Krispies are almost as old as Matthew Alice! And now, Jodie, it’s time for you to go out and play so the rest of us can get back to those really big, important grown-up questions.