Changes

Jump to: navigation, search

Quality Assurance

28 bytes added, 12:26, 17 April 2018
no edit summary
* [https://www.facebook.com/groups/MilkTheFunk/permalink/1710242802337260/ Another MTF thread on sanitation.]
====Efficacy of Cleaning Agents====
'''====Commercial cleaners and disinfectants'''====
Sodium hydroxide (caustic), [https://en.wikipedia.org/wiki/Ethylenediaminetetraacetic_acid EDTA (ethylene diaminetetra-acetic acid)], chlorinated disinfectants, and hydrogen peroxide-based disinfectants such as Pur-Ox from Birko or Lerasept-O from Loeffler are effective at breaking up biofilms when used in their highest recommended concentrations <ref name="Wirtanen_2001" /><ref>Brandon Jones. Private correspondence with Dan Pixley. 04/02/2018.</ref><ref>[https://www.reddit.com/r/TheBrewery/comments/6hqnvf/mtkettle_cleaning/dj0zd0s/ Levader on Reddit.com. "The Brewery". Retrieved 04/02/2018.]</ref>. Foaming agents that are often used in packaging lines for cleaning, however, might not be as effective. One study found that one foaming agent (VK10 Shureclean, which is sodium alkylbenzenesulphonate) required two times the maximum concentration that is recommended by the manufacturer to completely remove biofilms. In comparison, all of the sodium hydroxide (caustic) based cleaners that were tested were effective at completely removing biofilms in concentrations that were below the vendors' recommended maximum concentrations <ref>[https://link.springer.com/article/10.1007/s13213-010-0085-5#Bib1 Susceptibility of wine spoilage yeasts and bacteria in the planktonic state and in biofilms to disinfectants. Mariana Tristezza, António Lourenço, André Barata, Luísa Brito, Manuel Malfeito-Ferreira, Virgílio Loureiro. 2010.]</ref>. Peracetic acid (PAA) has also been shown to be effective against biofilms in the highest recommended concentrations but isn't as effective as the previously mentioned cleaners and should be used after a caustic cleaning cycle <ref>[https://www.researchgate.net/publication/273439407_Disinfectant_testing_against_brewery-related_biofilms Disinfectant testing against brewery-related biofilms. Storgårds, Erna & Närhi, Mikko & Wirtanen, Gun. 2001.]</ref><ref>[https://www.researchgate.net/publication/244994186_COMMERCIAL_SANITIZERS_EFFICACY_-_A_WINERY_TRIAL COMMERCIAL SANITIZERS EFFICACY – A WINERY TRIAL. Duarte, Filomena & López, Alberto & Alemão, Filomena & Santos, Rodrigo & Canas, Sara. 2011.]</ref>, but its effectiveness decreases below 20°C. Chlorine and iodine-based disinfectants destroy microbe at colder temperatures, however, they are less effective in the presence of wort or other residues. Chlorine-based disinfectants can cause pitting in stainless steel if left in contact for too long, and [https://ssbrewtech.zendesk.com/hc/en-us/articles/205602399-DO-NOT-USE-BLEACH-OR-CHLORINATED-CHEMICALS- some stainless steel manufacturers] recommend not using chlorine-based disinfectants at all (refer to your equipment and chemical manufacturers). Hot water is one of the most effective disinfectants, however, dry heat is not as effective at killing bacteria (one strain of ''L. brevis'' was able to withstand 80°C dry heat for 60 minutes) <ref name="Wirtanen_2001" />. Dry heat at higher temperatures will sterilize at 170°C for 1 hour or 190°C for 12 minutes and can be used to sterilize many metal and glass instruments. Flaming kills within seconds on surfaces <ref>Private correspondence with Dr. Bryan Heit by Dan Pixley. 04/12/2018.</ref>.
'''====Homebrew cleaners and disinfectants==== '''Five Star Star San'''
Five Star Chemicals product Star San is a popular acid anionic sanitizer sold to homebrewers because of its relative safety and ease of use. Claims that acid anionic sanitizers are not effective at killing yeast have been made on various internet forums <ref>[https://www.homebrewersassociation.org/forum/index.php?topic=24447.msg312961#msg312961 User 'S. cerevisiae'. American Homebrewers Association forums. 10/05/2015. Retrieved 04/11/2018.]</ref><ref>[https://www.homebrewersassociation.org/forum/index.php?topic=4576.msg52894#msg52894 User 'richardt'. American Homebrewers Association forums. 11/15/2010. Retrieved 04/11/2018.]</ref>. These claims are based on the food science textbooks, "Principles of Food Sanitation," by Norman G. Marriott and Robert B. Gravani (2006) and "Basic Food Microbiology" by George Banward (1989), which contain conflicting information about the effectiveness of acid anionic sanitizers, and neither source contains experimental data nor references to experimental data. Furthermore, the provided explanation, which is that acid anionic sanitizers supposedly don't work effectively against yeast and molds is because acid anionic sanitizers are negatively charged and yeast are also negatively charged yet bacteria is killed because it is positively charged, is biologically incorrect. According to [https://www.youtube.com/watch?v=0JC9n50RdVo Dr. Bryan Heit of Sui Generis blog], both yeast and bacteria have negatively charged cell walls, and this fact has been well established in microbiology since the 1940's (Dr. Heit has published several [https://scholar.google.com/citations?user=8yxqYNgAAAAJ&hl=en&oi=ao peer-reviewed scientific studies on cell wall polarity]).

Navigation menu