My roommates and I have come to a question none of us can answer. Why and what kind of mold grows on coffee pots after a couple of weeks? Is it unhealthy to let it stay that way or even do so much as to lift the slab of mold and pour a cup? Finally, if one were to put the aforementioned poured cup of coffee in a microwave, would it kill anything harmful left in the coffee? Let us know, we’d rather be informed before we experiment.
Well, a Google search turned up little in the way of specific taxonomy of coffeepot molds, although in my experience the molds appear to be the same ones that colonize bread in my cupboard and leftovers in my refrigerator.
However, I did find a page from the Royal Society of Chemistry in Canada soliticing photos of mouldy coffee cups in honor of the 75th anniversary of the discovery of penicillin – a happy accident in which rogue mold grew in a forgotten petri dish.
As for ingesting the mold, the CDC has an excellent resource page on household mold, although they expect most folks’ exposure will be respiratory.
One of the links there, however, does lead to an article in Clinical Microbiology Reviews that describes toxicology of household molds. It’s quite technical and loaded down with jargon. To summarize it: typical household mold colonies may contain one or more of many known poisonous strains, with ingestion effects including mild to severe allergic reaction, neurotoxicity, gastric distress, hallucination, impaired immune response, or even death due to complications of one or more of the above.
Not to mention the taste and smell. I can’t eat bread that even smells like it’s started going moldy, after being in an impoverished family as a child and fed moldy bread with the spots shaved off. “It’s fine. I scraped all the mold off,” mom said. But she didn’t scrape the smell off! I had enough PBJ&M sandwiches as a youth, TYVM!
I’ve seen various colors of mold (green, white, orange–hey, maybe it was Irish coffee!) growing on the surface of the same abandoned cup of coffee, so I doubt that there is a single factual answer to “what type of mold grows on coffee.” In the event that any of the molds is toxic, microwaving the mess might kill the mold, but that wouldn’t eliminate the toxins. So skip the experimenting and wash yer dishes.