Originally Posted by DrummoRC
...I am interested in opinions as to what the film is??? I am not sure if it could be some protein build up or some thing to do with with the pumpkin - as I never did a batch with pumpkin pure before Any ideas or experience related to possible contamination?
I'm not an expert on pellicles, although I grew a few like that, one on some harvested yeast. I still have it and will innocculate some saison with it
I think it's lactobacillus. It's all around us and your grain and flour is covered with it. Do not mill or weight grain anywhere near your brewing or fermentation areas. By racking to the secondary it could have been waiting in the carboy, cane, tubes, or just in the air. They are very opportunistic.
The pellicle gets formed in the presence of oxygen and its purpose is to shield the liquid underneath for the bacteria to do its work, souring the beer. The pellicle is made up of proteins, and the little bubbles you see is from CO2 being formed, below the surface. Quite a magnificent process and sight! Here is a thread to proudly show off your pellicles
If you can take a good picture of your pellicle before you disturb it, and post it in that thread you'd do the pellicle gazing community here such a great favor.
And you really should taste the beer underneath the pellicle before you decide to chuck it all. It maybe the best thing you ever had. And it won't kill you or make you sick.