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The presence of ethanol in concentrations of 1-4% encourages pellicle production in some strains of ''Acetobacter pasteurianus'' (although the presence of ethanol encourages pellicle formation, the amount of ethanol did not make a difference). In some strains of ''A. pasteurianus'', sugar encourages pellicle formation. It has been suggested that CPS production in ''Acetobacter'' is a function of stress tolerance by acting as a barrier around the cell that protects it from acetic acid in the environment. Strains that form a pellicle in the presence of ethanol and/or higher temperatures can fully ferment vinegar whereas those that do not create a pellicle perform poorly in comparison <ref name="Perumpuli"></ref>.
===Identification in Contaminated BeersPellicle Appearance as a Microbe Identifying Indicator===
(This section in progress)
An often asked question by homebrewers is can a contaminating or wild caught 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.