What is the white stuff floating in my infusions?

I recently made limoncello, strawberry vodka, and rhubarb vodka. I filtered them through cheesecloth and have them stored in the fridge in mason jars. Today I saw all three had a loose, white blob floating around. I've done Internet searches and can't find anything that describes what I'm seeing. Maybe mold (the limoncello was cut with simple syrup and the others are straight vodka, 40%, so I suppose they could grow something)? Otherwise, they are clear and smell ok. Any ideas? I'm new to this, so if these went bad fast, I want to correct it next time. I have 2 more infusions going now!