Brains On! Science podcast for kids · Brains On Universe

Is there such a thing as a blue raspberry? And why are raspberries hairy?

March 31, 2026·27 min·2 clips

In 1976, the FDA banned red dye number two after linking it to cancer, leaving ice pop makers scrambling for a way to tell their flavors apart.

Raspberry hair gets the headline question. The excerpt spends its best science stretch on actual raspberries, where a snack suddenly has a lot going on. First up are the long yellow strands. The guest explains that they are styles, parts of the plant’s reproductive system that helped the flower get pollinated and turn into fruit. It is a small detail, but a good one. The berry does not become homework. The hosts keep pointing to things kids can see: droops, fuzz, and tiny stem-like hairs. Then the silliness walks right in. Peachy celebrates being shaved so well that he looks like a nectarine, which keeps the plant lesson loose instead of stiff. The white fuzz stays unresolved for a bit. The host saves that answer until after Mr. Peaches gets rinsed and towelled off, then uses the pause to move into the mystery sound. The sound is loud, strange, and hard to pin down. The kid guesses aggressive knocking, maybe someone banging on a table, then hears a rhythm that could be drums. Nobody acts like the guess has to be perfect. That is part of the charm. The show lets the guesses wobble before the answer comes after the credits. A live show note opens the episode, with added San Francisco and Toronto shows plus other cities where the Brains On team hopes to meet listeners. Around the edges, there are tour notes and names. At the center, though, is a simple kid question, a real observation, and a science answer padded with jokes. Raspberry hairs stop looking random. They start looking like clues from a flower’s earlier life.

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