What are some signs of infection? Everyone advices that we anally watch over our wort so that infection won’t set in. But what would be a sign that your beer was infected? I just put a light lager in the secondary to begin the lagering phase. I noticed some little target like looking films on top of the fermented beer. It literally looked like a perfect round target. I felt it with my hand and it was very cohesive. Not sure if this means my beer is infected. It took forever (about one week) for the fermentation to begin. I had to check the gravity several times to see if anything was happening. Any thoughts?
I’ve had beers get infected before, but it has never been visible. I’ve always detected it by smelling or tasting the off character (most commonly sour or band-aidy).
I recently had a wild yeast infection. The ferment took 72 hours to kick off. Never skipping a starter again. The ferment was very cloudy, never cleared up which was my first indication of something wrong. Final gravity was about 1.002 and tasted like solvent.
Yep…I had a Celebration clone that finished 6 points lower than predicted because it was infected. Looked great, but smelled and tasted awful. My first post, by the way. 8)
If you are putting your hand on your beer, that might be a sign it’s about to be infected.
It might be a surface mold - I would pull it off (carefully, with a sanitized spoon) and see what happens.
Did it attenuate to where you wanted? How did the FG sample taste?
Actually, watching over your wort won’t do anything. Proper sanitation is the only way to prevent infection. 
A picture would help, but if it felt semi-solid that’s probably not good. If it’s done fermenting you could rack the beer from under it and hope it was all on the surface.
Infected beer can be cloudy, sour tasting, phenolic in nature (flavor/aroma), floating debris, etc…
It can be one or more of these issues. Post a pic if you can. That may help.
You can’t always go by smell during primary initially. Normally, infections take time to manifest themselves.
I’d pull a sample with a thief and taste it. The only way you’re going to know for sure.