Changes

While using agar plates to isolate yeast colonies is the most effective way to culture wild yeast, it is not the only way. Wild yeast should first be caught using DME wort as outlined in [http://bootlegbiology.com/diy/capturing-yeast/ Bootleg Biology's ''Method 1'' or ''Method 2'']. Hopping the wort will help decrease bacteria if that is desired. The wort's pH should be lowered to below 4.5 0 with lactic acid to avoid bacteria as much as possible. Molds may still grow in the yeast starter even with the lower pH, and should be removed by scraping them off of the surface of the wort. Signs of a small krausen within 1-3 days is a good sign that viable wild yeast has been collected. After another few days, the yeast will start dropping to the bottom of the collection vessel <ref name="manoaction">[http://www.homebrewtalk.com/collecting-wild-yeast.html Collecting Wild Yeast. Manoaction. Homebrewtalk. Oct 30, 2012.]</ref>.

Once the wort has fermented out (allowing 2 weeks total is a good rule of thumb), decant the beer and pitch the collected yeast into 500ml of starter wort, again lowering the pH of the starter wort to below 4.5 0 by using lactic acid. After the starter wort has been fermented, the yeast should have enough of a population to ferment out a 1 gallon batch of wort. Keep the recipe of the wort simple, and in the 1.050 gravity range. The population of the yeast should be high enough to out-compete bacteria and lower the pH of the wort within a few days, so the pH of the 1 gallon batch does should not need to be lowered. After fermenting out the 1 gallon batch of beer, first smell the beer. If it tastes like feces or vomit, do not sample it and throw it away. If the beer smells ok, feel free to sample the beer to see if the wild yeast is usable or notproduced a good tasting beer. Fermenting a few batches of beer at different temperatures is a useful method for identifying the ideal fermentation temperature range for the yeast. Wild yeasts can be highly or moderately estery, or could have undesirable flavors <ref name="manoaction"></ref>. If  ===Safety===An often asked question when it comes to tasting beer fermented from a wild culture is, "When is it safe to drink?" To our knowledge, no studies have shown when a wild caught beer is safe to drink. However, several studies can give us some guidance on this.  * The addition of hops in the starter wort will kill gram positive bacteria pathogens (''L. monocytogenes'' and ''S. aureus'') <ref name="Menz1">[http://www.ncbi.nlm.nih.gov/pubmed/22004814 Growth and survival of foodborne pathogens in beer. Menz G., Aldred P, Vriesekoop F . Oct 2011.]</ref>.* A low pH is not the only requirement for making beer safe. A combination of alcohol, low pH, and hops will ensure that pathogens cannot grow <ref name="Bryan">[http://suigenerisbrewing.blogspot.ca/2014/02/fact-or-fiction-can-pathogens-survive.html ''Fact or Fiction? Can Pathogens Survive in Beer?'' Sui Generis Blog, by Bryan Heit.]</ref><ref>[http://www.ncbi.nlm.nih.gov/pubmed/20207437 The growth and survival of food-borne pathogens in sweet and fermenting brewers' wort. Menz G1, Vriesekoop F, Zarei M, Zhu B, Aldred P. May 2010.]</ref>. * Two studies have shown that ''E. coli'' can survive in moderate strength beer for at least 28 days (more than 30 says in one study) if the beer is stored cold (39-41°F or 4-5°C) <ref name="Menz1"></ref><ref>[http://www.ncbi.nlm.nih.gov/pubmed/24674433 Survival of foodborne pathogenic bacteria (Bacillus cereus, Escherichia coli O157:H7, Salmonella enterica serovar Typhimurium, Staphylococcus aureus, and Listeria monocytogenes) and Bacillus cereus spores in fermented alcoholic beverages (beer and refined rice wine). Kim SA1, Kim NH, Lee SH, Hwang IG, Rhee MS. March 2014.]</ref>. Therefore, the wild culture should be stored at room temperature for a least a month before tasting. Additionally, the pH of the beer should be less than 4.5, and alcohol should be present for at least one month before tasting. The smell of feces or vomit indicates that these bacteria may be present; dump it out if so. <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/1104757552885791/?comment_id=1104851526209727&offset=0&total_comments=8&comment_tracking=%7B%22tn%22%3A%22R1%22%7D Conversation with Bryan Heit on MTF regarding when it is safe to taste wild beer. 7/5/2015.]</ref>.* In unfermented wort, ''E. coli O157:H7'' and ''Salmonella Typhimurium'' were shown to grow at a pH of 4.3, but stopped growing at a pH of 4.0 <ref name="Menz1"></ref>. Since the flavors are undesirablebeer of a starter can be decanted, discard adding enough lactic acid to get the yeast starter wort down to 4.0 won't effect the taste of the final beer, and try catching is a a different good extra precaution.* In the words of Bryan Heit from Sui Generis Blog: "''If you have an immunodeficiency or are immunosuppressed: Obviously, don't take medical advice off the internet. Talk to your MD to see if you are at risk of infection - especially if you're condition/treatment increases your risk of fungal infections. If so, or if you are concerned, stick to beers that are fermented using commercial strains of Saccharomyces yeast.''" <ref name="Bryan"></ref>