I have been struggling with really low temps while fermenting with start and stop fermentations. Below is a picture of a film that has formed on the top of the wort in the secondary. I transferred a little early from my primary to my secondary (4 days). The beer has been in the secondary for 12 days now and I took a reading 7days ago and got 1.018. Today when I took a reading I got 1.018 again and noticed this film.
I think the film is just a thin, secondary krausen and is yeast (I hope). The beer tasted OK with no sour or off flavors. No taste of residual sweetness. The picture is the best I can do and is not the best I realize. I am a little surprised that what looks to be active if slow fermentation but no drop in my gravity. But I only heat with wood and I'm fighting cold overnight temperatures (dropping to mid 50's).
Yeast is Wyeast 1968. OG was 58. Total time since pitching is
Question: Why am I seeing what I think is fermentation but no drop in gravity? Unless that isn't yeast on top (No!....). Guess I'll wait and hope the thang ain't stuck.