Changes

Although little studying has been done on mold growth in beer, it has been known to occur in barrel aged beers are fruited sour beers. Oxygen generally needs to be present in order for mold to grow. Mold growth on fruit that is in sour beer can occur if the fruit is floating above the surface of the beer, and enough oxygen is present (either from vacuum suck-back, the oxygen permeability of the vessel, or sampling). For this reason, many commercial sour brewers will "punch down" the fruit frequently with a dish-like tool. ===Mold Growth in Wild Mead===It has been demonstrated that while honey is antimicrobial due to its high sugar concentration and low water concentration, which inhibits the growth of microbes, honey is not inherently pasteurized and sanitary. Low levels of molds, yeasts, and spore-forming bacteria can survive in honey and can begin to grow once the honey is diluted with water as it is in mead-making. It is thought that most of the microbes found in finished honey originate from the handling of the honey, and do not originate from the hive, although some microbes may be introduced from the bees <ref>[https://www.sciencedirect.com/science/article/pii/0168160596009701 Microorganisms in honey. Jill A Snowdon, Dean O Cliver. International Journal of Food Microbiology. Volume 31, Issues 1–3, August 1996, Pages 1-261996.]</ref>. It is therefore possible that mold growth can occur during mead making if the mead does not begin to ferment in a timely manner, for example, for wild/spontaneous fermentation <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/2140692022625667/ Adam Johnson. Milk The Funk Facebook group post on preventing mold growth. 06/21/2018.]</ref>. To prevent mold growth during wild fermentation of mead (with no lab yeast pitched), purging the vessel with CO² until after the mead begins actively fermenting should help reduce the chances of mold growth.