Changes

* Monitor for mold growth. If mold begins to grow on the growth media, scrape it out and continue on with the isolation process. This should be safe since isolating the yeast will separate it from any potential mycotoxins that developed during the initial catching. Do not consume any growth media that has had mold grow on it (see [[Mold]]). One suggested method is to remove any materials (fruit, leaves, etc.) that were used as an inoculant as soon as visible fermentation happens; this can help avoid mold growth by removing floating material <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/1812527172108822/?comment_id=1812566615438211&comment_tracking=%7B%22tn%22%3A%22R%22%7D Caroline Whallen Taggart on removing fruit to prevent mold. Milk The Funk Facebook group. 09/05/2017.]</ref>.

* In general, summer and spring are more successful times to catch wild yeast, however any time of year can be successful. Simply choose fruits or flowers that bloom/grow during that particular season. For example, in spring, flowers and fruit blossoms are a good source. In summer, wild summer fruit can be a good source (raspberries, strawberries, cherries, etc.). In the fall, apples and grapes can be a good source. In winter, juniper berries <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/1683379841690223/?comment_id=1683799054981635&comment_tracking=%7B%22tn%22%3A%22R%22%7D Milk The Funk thread on the best seasons for bioprospecting. 05/11/2017.]</ref>.

* [https://www.facebook.com/groups/MilkTheFunk/permalink/1034954619866085/ David Thornton's use of foam as stoppers.]

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 4.5 with 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 yeast cell count should be high enough at this point to out-compete bacteria and lower the pH of the wort within a few days. The pH of the 1 gallon batch, therefore, does not need to be lowered, although the brewer may choose to do so anyway. For [[Wild_Yeast_Isolation#Safety|safety reasons]], test to make sure that the beer fully attenuated and has a pH of 4.5 or less. Allow for one month after fermenting the 1 gallon batch of beer before sampling. If it smells 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 produced a good tasting beer. David Thornton from [[SouthYeast Labs]] estimates that only about 10% of yeast that can fully attenuate produces favorable results, so failures are to be expected (keep trying!) <ref name="Thornton"></ref>. Fermenting a few batches of beer at different temperatures is a useful method for identifying the ideal fermentation temperature range for the yeast.

See also: