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===Biofilms===
Many microorganisms can form ''biofilms'' which is defined as a community of cells of one or more species that are attached to each other and/or a surface and are embedded in a matrix of extracellular polymeric substances (EPS), including polysaccharides and proteins, similar to a [[Pellicle|pellicle]]. Biofilms allow microbes to survive less vigorous cleaning and sanitizing regiments and chemicals and has become a concern in the food industry as well as in the brewing and winemaking industries <ref>[https://onlinelibrary.wiley.com/doi/abs/10.1111/1541-4337.12087 The Paradox of Mixed‐Species Biofilms in the Context of Food Safety. Iqbal Kabir Jahid and Sang‐Do Ha. 2014.]</ref>. Biofilms most often form in the packaging system somewhere, but can also be found on side rails, wearstrips, conveyor tracks, drip pans, and in-between chain links <ref name="storgards_2000" />.
Bacteria and yeast form a biofilm in two stages, which are determined by a number of variables. In the first stage, the microbes remain in their [http://www.dictionary.com/browse/planktonic|"planktonic"] form (floating around in the liquid), but they begin to adhere on surfaces and to each other as those surfaces. Other species of microbes can also be adhered to during this phase. The second stage is where the microbes start producing exopolysaccharides (EPS) which helps them bind together in a matrix, along with any available proteins and exopolymers produced by the bacteria. A large portion of biofilms is actually water (80-80%) as this allows the microbes to remove waste and consume nutrients. This matrix helps the microbes resist antibiotics, UV radiation, and cleaning chemicals. Gene exchange also occurs more frequently. At the end of this second stage, the microbes become attached to surfaces in such a way that is permanent without the use of cleaning chemicals. This is known as the microbe's [http://www.dictionary.com/browse/sessile|"sessile"] form (immobile). Bacteria in this form continue to multiply, and upon maturation of the biofilm, eventually, planktonic cells begin to be produced and released from the biofilm to find new homes. They also display different phenotypes, which might contribute to their ability to resist cleaning chemicals. Rough or scratched surfaces are more prone to biofilm formation due to the higher surface area. Hydrophobic surfaces, such as Teflon and other plastics) are more prone to biofilm formation than hydrophilic surfaces (glass and metal) <ref>Biofilms in the Food and Beverage Industries. P M Fratamico, B A Annous, N W Guenther. Elsevier, Sep 22, 2009. Pp 4-14.</ref>. Biofilms can form within 2-4 days <ref name="Wirtanen_2001">[https://www.researchgate.net/publication/273439407_Disinfectant_testing_against_brewery-related_biofilms. Erna Storgårds, Gun Wirtanen. 2001.]</ref>.