Floating on top

[maulotaur]

I have viewed several sugar washes and a molasses wash running through a pot still and there was a substance floating on top of the alcohol. This was not just on one or two of the containers, but every one of them. I was thinking it may be fusel oils, but from what I read it didn't seem normal to be on every jar. Speed through a pot still can be an issue, but this is running with the heat at a level to get the vapor to condense just a tad faster than drops--at least until well into the tail end of things. The floating looks like powdery oil spill. Seems to congeal together. It disappears if filtered through a coffee filter. Any ideas or suggestions? Thanks in advance!