I have only seen 3 mothers of vinegar in my life. Once in a bottle of white vinegar I found hiding in the back of the pantry while packing for one of my vagabond moves, and 2 yesterday when I needed vinegar for a vinaigrette. Both new finds were in a bottle of white wine vinegar. They look gross and nasty, but this time I knew that they were harmless. I had done some internet searching the first time I saw one. Here and here are examples of what’s available for information online.
Finding a slimy, jellyfish looking thing in your pantry can be kind of creepy.
When Andy saw it today he was 6 kinds of freaked out.