But Why: A Podcast for Curious Kids

Why do apples have stems? Why do fruits start out as flowers? How did the first apple grow when no one was there to plant its seed? Why can you make a seedless grape and not a seedless apple? Why are apples so juicy? How is apple juice made? Why are apples hard and pears soft? In this episode we take a field trip to Champlain Orchards in Shoreham, Vermont to learn more about apples. Our guides are 10-year-old Rupert Suhr, his father, Bill, and apple expert Ezekiel Goodband.

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Flower to Fruit Image

Why are some fruits a flower before they’re fruit? - Grayson, 8, San Jose, California

Actually ALL fruits start as flowers (but not all flowers turn into fruit). Growing fruit is a way that some plants reproduce. Fruit is the nice ripe container that holds the seeds, which humans or animals will eat and then spread around (often through their poop), allowing new plants to grow.

But that process begins with a flower. The outer part of the flower often has beautiful colors and shapes and smells—and that’s all part of the way the plant tries to attract a bee or other pollinator:

“The flower has an ovary at the base of the petals. The petals are enticing a bee to come with the pollen from another blossom that it’s visited and there’s some nectar that the bee can collect and while the bee is doing that it’s shedding some pollen,” explains Ezekiel Goodband. “That pollen completes the information that the apple needs to start growing. So the flower is to attract the bee.”

That ovary at the base of the flower will start to grow and that will become the apple that you eat. If you look at the bottom of an apple—the opposite end of where the stem is attached to the tree—you can actually see where the flower used to be. It even kind of looks a little bit like a tiny flower.

We're marking the winter solstice with an episode all about snow! Why do snowboards look like skateboards? We get an answer from Burton Snowboards. How is snow made? Why is snow white? Why are all snowflakes different? We'll hear from Jon Nelson, author of "The Story of Snow: The Science of Winter's Wonder." Also why does snow melt? And where is the deepest snow?

Why do lions roar? Why do crickets chirp? Why do bucks shed their antlers every year? How can porcupines and hedgehogs avoid poking themselves? Do fish pee? What is the fastest fish? What do jellyfish eat? A roundup of animal questions, with answers from Paola Bouley of Gorongosa National Park in Mozambique, Kent McFarland of the Vermont Center for Ecostudies, naturalist Mary Holland and Jo Blasi of the New England Aquarium.

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Kids love cheese! (So do adults: Americans consume an average of 40 pounds of cheese per person per year.) In this episode we learn how cheese is made and answer all of your cheesy questions: Why are there different types of cheese? Why do cheeses have different flavors? How do you make Colby Jack cheese? How does cheese get its color? And why do we say cheese when we take a picture? We visit the Cabot Cheese factory and talk with Maegen Olsen and Panos Lekkas.

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• Cheese starts with milk. Cheese is often made with milk from cows or goats, but it can also be made with milk from sheep, buffalo, camels or other mammals. (There’s even a moose-cheese company in Russia!) If the cheese is made in bulk to sell to lots of people, companies will usually run tests on the milk before they turn it into cheese. They want to make sure it doesn’t have bad bacteria or antibiotics in it. The milk is then pasteurized, which means it’s heated quickly and cooled quickly to kill any lurking bad bacteria.
• Next cheesemakers will add a starter culture. Starter culture is GOOD bacteria, which will eat the milk sugar (lactose), create lactic acid and drive down the pH of the milk. That helps create curds.
• The next step is coagulation! (Coagulation is the process of turning a liquid into a semi-solid or solid.) To coagulate the milk, an enzyme called rennet is added.
• Now it’s time to separate the curds from the whey. Cheesemakers will use knives to cut the coagulated milk into chunks known as curds, leaving some liquid behind. That liquid is known as whey. When milk is made into cheddar it gives a 10% yield, meaning 10% of the milk will become cheese and 90% will be left over as whey. Some cheesemakers, like Cabot, use the whey to make protein powders. In other factories it might go to waste.
• Next, it’s time to add salt. Salt serves as a preservative and gives the cheese flavor. If it’s a flavored cheese, things like garlic or peppers will be added at this point.
• The cheese is then pressed into blocks. At factories like Cabot, they pull the curds into tall towers and then add more and more, creating pressure that forms those curds into solid blocks. Smaller cheesemakers use a cheese press.
• In the final step, the cheese is aged. It will sit in a cold storage or cheese cave and just...get older. Cheddar can be aged for years, giving it a stronger flavor. Aging also changes the texture of a cheese like cheddar. It can get more crumbly the older it gets. Once it’s ready, it will be cut, packaged and shipped to stores.

This week, we're getting out our bug nets and talking about dragonflies and ladybugs! Why do ladybugs have spots? How many different types of ladybugs are there? How do they crawl on the ceiling without falling down? Where do dragonflies and ladybugs sleep? Why are dragonflies called dragonflies? Do they bite? We're joined by Kent McFarland, a research biologist at the Vermont Center for Ecostudies and the co-host of another great VPR podcast called Outdoor Radio.

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