Kitchen Science 3-minute video · ages 4-8 · free coloring page
Why does a Halloween pumpkin get mushy?
You carve a pumpkin with a big happy smile. But a few days later, it is soft, saggy and mushy. Why does that happen?
3 min
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Free coloring page
The scene from the video as a coloring page, plus the three-sentence answer, the experiment, and a QR code back to this page. One sheet, US Letter, black and white.
The answer in three parts
Why?
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A whole pumpkin wears a suit of armor.
Its thick, tough skin keeps the water in, and it keeps tiny visitors out. So a whole pumpkin can sit on the porch for weeks and weeks. But when you carve it, you cut doors and windows in the armor!
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Tiny travelers land on the soft, wet inside.
The air is full of tiny travelers, much too small to see. Some are mold seeds, called spores. Some are bacteria. A carved pumpkin is perfect for them. It is wet, it is full of food, and nothing is in the way. So they land, and they start to grow.
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They turn the pumpkin into mush.
Molds do not have mouths! They let out special juices that turn the firm pumpkin into soft mush, and then they soak it up. The walls get softer and softer, the smile droops, and fuzzy spots show up.
For grown-ups: The pumpkin is also losing water through its cut edges, so it wrinkles and shrinks, like a grape turning into a raisin. To keep a jack-o'-lantern smiling longer, carve it just a few days before Halloween and keep it in a cool, shady spot. If you see the fuzz, just look - don't touch it or sniff it.
A tiny experiment
Try it!
Fridge or counter?
You need: two small pieces of pumpkin, two clear bags, and a grown-up to do the cutting
- Ask a grown-up to cut two small pieces of pumpkin and seal each one in a clear bag.
- Put one in the refrigerator, and leave one on the counter.
- Look every day, but keep the bags closed. Which piece gets fuzzy first?
What happened? Mold grows fastest when it is warm and wet. When it is cold, it grows very slowly. That is why food stays fresh longer in the refrigerator.
Did you know?
Molds and bacteria are nature's recyclers! They turn old pumpkins and fallen leaves back into rich soil, so new plants can grow.
When you are done with your pumpkin, put it in the compost, and it can help next year's garden grow.
Your guide in this video
I'm Fuzzy, a tiny bit of mold. Please don't be mad at me, I'm one of nature's recyclers!
Fuzzy is a little fluffy gray-green mold puffball. The tiny pink bean-shaped bacteria float around with Fuzzy.
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