ask dr. vinny

Hello there! I'm Dr. Vinifera, or "Vinny" for short. Ask me your toughest wine questions, from the technical aspects of winemaking to the fine points of etiquette. I hope you find my answers educational and even amusing. Looking for a particular answer? Check my archive and my FAQs. You can also follow me on Twitter: @AskDrVinny.

Dear Dr. Vinny,

After drinking red wine from a Solo cup, I left the mostly empty cup sitting out for a week (please don’t judge). However, after that week I noticed thousands of uniformly distributed wine-colored speckles inside my cup. What is that?

—Jenna B., Gainesville, Ga.

Dear Jenna,

Judge? What is there to judge about drinking wine from plastic cups that you don’t clean up for a week?

My guess is that you have started making vinegar without trying. Mycoderma is a type of bacteria that can grow on the surface of a wine exposed to air. If you leave that cup out for another couple weeks (not judging!), after a while these specks will become more gelatinous and mucousy and sink to the bottom, and then you’ll have a vinegar mother.

Of course, if you’d like to make vinegar from leftover wine by actually trying to, you can check out my tips.

—Dr. Vinny

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