Can a beer mold in the secondary?

I have a stout, fortified with 3 cups of cold-press espresso roast coffee and two vanilla beans in the secondary. It has been 10 days at 67 degrees and I went in to look at it today. There is an oily residue on the top, that I thought might be oils from the coffee, but there is also a more solid, multi-colored mold-looking substance covering part of the beer. I tried to take a photo, but it does not show up as anything.

This leads me to two questions:

1. Has anyone else ever seen this?

2. Is my beer ruined, or should I just leave the trub and the top in the secondary on brewing day?

Could be an infection... I've never used coffee in a beer but I wonder if it needs to be sanitized in some way.

You can get mold or an infection, but if everything was sanitized and properly sealed with an airlock, you wont.

The secondary is low in PH, low in nutrients, high in bacteria competitors (the yeast colony) and high in alcool. It is not an easy place for bacteria to spread, but sanitizing is always a good procedure.

Could be an infection, but it could be a part of the final fermentation as well. I suggest to leave it alone for some days and see. If the mold becomes furry it is definitly gone

You remind me a dark belgian batch that I made some years ago with a friend of mine. The fermentation smell was very strong and I thought it was gone. The friend of mine convinced me to proceed and to bottle anyway. It turned out it was fine.

Good luck
Marcello

A question: are you sure that any infection hasn't started directly into the primary?
Anyway, the wait and see is still good...