WHAT the heck is growing on my spackling compound?

Question

My drywall (plaster) spackling compound has been sealed up for a year last time I used it. When I opened it yesterday, it had what looks like mold (fuzzy, white) growing on it. What can survive on spackling compound (gypsum and water)? What does it metabolize???

I just heard that they smooth out the compound with wheat flour, so that must be what the fungus is eating...

Answer 1

It is most likely a fungi or a water mold, but it's hard to say which without more information.

Many fungi will grow just fine on drywall. I couldn't tell you what it lives on in spackling compound though.