Mystery #1Tier 2microbes / fungi

Why does bread go mouldy?

Leave a slice of bread out for a week and fuzzy green-grey patches appear — yet you never sprinkled anything on it, and it was perfectly fine when you bought it. Where does the mould come from, and why does it spread?

A slice of bread covered in fuzzy mould — Photo: Airear · CC BY-SA 4.0 · via Wikimedia Commons

Your guess

What's your hunch — where does the mould on old bread come from?

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