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An often asked question by homebrewers is can a contaminating microbe be identified based on the appearance of a pellicle. This is a difficult exercise for a few reasons.
# Numbers and size of bubbles in a pellicle is created by trapped CO2, and thus is not an identifying feature.
# Scientific research on pellicle formation in beer is currently next to none.
# Identification of microbe species and sometimes even genus under a microscope based on cell morphology alone is not enough to be certain of that identification (see [http://suigenerisbrewing.blogspot.com/2014/12/brett-trois-riddle-wrapped-in-mystery.html this article on Trois genera identification] as an example), let alone attempting to identify microbes based on a visual "macro-level" formation such as a pellicle.
# DNA analysis of a microbe is the only way to reliably identify the species of a microbe. This is why [http://bootlegbiology.com/2015/09/17/local-yeast-project-study-barrel-culture-t-shirts/ Bootleg Biology is launching a program to identify wild caught microbes through DNA analysis].
The above stated, it might be possible to make an educated guess as to the genus of microbe that produced a pellicle if there was a controlled study (same wort, same incubation conditions, etc.) that examined the visual differences between pellicles formed by different genre of microbes. Unfortunately, such a study has not been performed that we know of. Thus, it is unknown if the genus of a contaminating microbe can be determined based on the visual appearance of the pellicle alone <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/1153845284643684/?comment_id=1153891934639019&reply_comment_id=1154095574618655&total_comments=5&comment_tracking=%7B%22tn%22%3A%22R2%22%7D Conversation with Richard Preiss and others on MTF. 09/24/2015.]</ref>.
==Handling/Racking==