9
edits
Changes
m
→Reducing Microorganisms
Most brewing equipment should be designed for good hygiene. Pits and crevices should be avoided, and all surfaces should be smooth when possible. All equipment and pipelines should be self-draining. Valves are a typical source of contamination because they are not easily CIP'ed, especially plug valves and ball valves (although butterfly, gate, and globe valves are also difficult to CIP) <ref name="storgards_2000" />. Horizontal surfaces and wet surfaces are more prone to biofilm formation. In one study that compared biofilm formation in bottling lines versus canning lines, it was found that canning lines develop less microbial biofilms and contaminations than bottling lines due to not having rinsing stations, labeling stations, and simpler constructions than the bottling lines that were studied <ref name="Storgårds_2006" />. However, some canning lines cannot use caustic for cleaning, or it is not common practice, but use foaming agents instead which are less effective at removing biofilms (see [[Quality_Assurance#Efficacy_of_Cleaning_Agents|efficacy of cleaning agents below]]). The lack of use of caustic cleaners in canning lines has been identified as a source of contamination issues with [[Saccharomyces#Saccharomyces_cerevisiae_var._diastaticus|''Saccharomyces cerevisiae'' var. ''diastaticus'']] in canning lines <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/1561762887185253/?comment_id=1791471917547681&reply_comment_id=2017381731623364&comment_tracking=%7B%22tn%22%3A%22R9%22%7D Caroline Smith from Lallemand. Milk The Funk Facebook group post on diastaticus contamination. Feb 2018.]</ref>.
Some other methods have been proposed by scientists as being novel ways to reduce unwanted microorganisms. These include exploiting naturally produced toxins. For example, some lactic acid bacteria [[Lactobacillus#Bacteriocins|produce bacteriocins]] which can kill other bacteria. Some strains of wine yeast can [[Saccharomyces#Killer_Wine_Yeast|produce zymocins]] that kill other species of yeast. Such methods are viewed as being fairly extreme. Advances in genetic engineering techniques make these approaches technically possible, however, there currently exists a commercial stigma against genetic modification. Additionally, there are many times types of toxins which target only specific species, so anticipating which species should be targetted could be challenging <ref name="Vaughan_2005" />.
===Cleaning and Sanitizing===