Well I've got trouble on my hands with my latest batch of a negra modelo clone. I've had it in the secondary now for about a week(4 total weeks) and I came home today to find a thin film on the top layer of my wort. The film consists of small bubbles that are somewhat connected to eachother. check out the pic. Please let me know what you think.
beer on Flickr - Photo Sharing!
beer on Flickr - Photo Sharing!