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Mold
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===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 or 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. Honey can start to ferment when it contains as little as 17% water, and at 19% water honey is very likely to ferment. 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><ref>[http://journals.tubitak.gov.tr/veterinary/issues/vet-13-37-5/vet-37-5-20-1301-46.pdf Microbiological and parasitological quality of honey produced in İstanbul. Emek DÜMEN, Hayrettin AKKAYA, Gülay Merve ÖZ, Funda Hatice SEZGİN. 2013.]</ref>, including botulism spores that can cause death to infants under 12 months old <ref>[http://jfoodprotection.org/doi/pdf/10.4315/0362-028X-44.11.812?code=FOPR-site Incidence and Origin of Clostridium botulinum Spores in Honey C. N. HUBTANEN, D. KNOX, and B. SBIMANUK. 1981.]</ref><ref>[https://www.mayoclinic.org/healthy-lifestyle/infant-and-toddler-health/expert-answers/infant-botulism/faq-20058477 "Infant and toddler health". Jay L. Hoecker, M.D. Mayo Clinic website. May 15, 2018. Retrieved 09/20/2018.]</ref>. While normal mead making procedures limit the potential of mold growth due to pitching healthy yeast and a fast start to fermentation, it is possible that mold growth can occur when attempting to ferment mead spontaneously by not adding any laboratory yeast because of the lag time for fermentation to begin <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 spontaneous fermentation of mead (also known as "wild fermentation" or "native fermentation"; see [[Mead#Alternative_Fermentation_Techniques|Mead]]), purging the vessel with CO<sup>2</sup> until the mead begins actively fermenting should help reduce the chances of mold growth. Lowering the pH to 4.5 will also help prevent mold growth, as well as a starting gravity at or below 1.070 because higher gravity must takes longer to start fermentation, which gives more opportunity for mold to grow before fermentation begins <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/2140692022625667/?comment_id=2142696379091898&reply_comment_id=2144309682263901&comment_tracking=%7B%22tn%22%3A%22R8%22%7D Justin Amaral. Milk The Funk group thread on mold in spontaneously fermented mead. 06/23/2018.]</ref>.
See also:
* [[Mead#Spontaneous|Microbes found in honey.]]
===Preventing Mold Growth===
===Health Concerns===
A small number of molds can produce poisonous substances called mycotoxins, or cancer-causing poisons called aflatoxins. Some molds that do not produce toxins can still cause allergic reactions or respiratory problems <ref name="usda"></ref>. Their effects are cumulative, rather than immediately toxic as in the case of pathogenic bacteria. A small amount of ingested mycotoxin won't be harmful right away, but it will increase the risk of gastric, intestinal, and colon cancer, as well as other health issues <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/2137444642950405/?comment_id=2137519622942907&reply_comment_id=2137542839607252&comment_tracking=%7B%22tn%22%3A%22R2%22%7D Dr. Bryan Heit Heit. Milk The Funk Facebook group thread on the health risks of mold. 06/19/2018.]</ref>. As a general rule of thumb, pigmented molds (non-white/grey) are more likely to produce poisonous substances (especially black mold which could be ''Aspergillus''), however, there are exceptions to this guideline <ref name="Dr. Bryan Heit">[http://suigenerisbrewing.blogspot.com/2016/08/fact-or-fiction-can-pathogens-survive.html "Fact or Fiction? Can Pathogens Survive in Beer - Mould Edition." Dr. Bryan Heit of Sui Generis Blog. 08/11/2016. Retrieved 08/11/2016.]</ref>. Some mycotoxins can survive boiling temperatures in wort to varying degrees, so if mold develops during processes such as kettle souring, it is possible for some percentage of mycotoxins to survive the wort boiling process and fermentation (one study showed that 20-30% of two mycotoxins were removed during boiling and fermentation) <ref>[http://www.sciencedirect.com/science/article/pii/S0168160507003984 Stability of mycotoxins during food processing. Lloyd B. Bullerman, Andreia Bianchini. 2007.]</ref>. Only mold that is growing on in contact with the beer itself is considered potentially dangerous; mold growing in airlocks or outside of vessels should not be a cause for concern as long as they do not come into contact with the beer itself. If only a small amount of mold has grown on the beer, then removing it quickly and purging the vessel with CO<sup>2</sup> to prevent more mold growth will limit the potential for exposure to toxins. However, if a large amount of mold has grown and if it happens to be a mycotoxin-producing species, then there is a higher chance that more toxin could be in the beer <ref name="Dr. Bryan Heit" />.
Identifying mold based on what it looks like is not a reliable way to determine if a mold is a cause of concern for health <ref name="Dr. Bryan Heit"></ref>. There are [https://www.google.com/search?client=firefox-b-1&ei=Ww08W-fWOabX0gK73K6YBg&q=mold+testing+lab&oq=mold+testing+lab&gs_l=psy-ab.3..0l2j0i20i263k1l2j0l6.127585.128971.0.129112.16.14.0.0.0.0.181.1496.0j12.12.0....0...1c.1.64.psy-ab..4.12.1491...0i67k1j0i131k1j35i39k1j0i131i20i264k1j0i20i264k1.0.5QReSMbR0GU mold testing labs] that are available that might be able to identify whether the mold is toxic or not. If mold is present in beer, commercial breweries should remove the mold and send it to a lab to check if it is a toxic mold before allowing the beer to be consumed. Some homebrewers may decide to risk taking a chance that the mold will not cause illness, however, we recommend discarding beer that has come into contact with the mold, especially if serving to others. Soft fruits and vegetables with high moisture that grow mold on the surface can also be contaminated with mycotoxins or aflotoxins below the surface, therefore beer or wort that has mold growing on its surface could also be contaminated below the surface <ref name="usda"></ref>.
See these resources on mold and mycotoxin:* [https://www.who.int/news-room/fact-sheets/detail/mycotoxins Mycotoxins key facts from the World Health Organization.]* [http://www.fsis.usda.gov/wps/portal/fsis/topics/food-safety-education/get-answers/food-safety-fact-sheets/safe-food-handling/molds-on-food-are-they-dangerous_/ct_index USDA website.], * [http://ucfoodsafety.ucdavis.edu/files/26438.pdf this UC Davis Food safety sheet.], and * [http://suigenerisbrewing.blogspot.com/2016/08/fact-or-fiction-can-pathogens-survive.html "Fact or Fiction? Can Pathogens Survive in Beer - Mould Edition.," by Dr. Bryan Heit of Sui Generis Blog.] for more information MTF threads:* [https://www.facebook.com/groups/MilkTheFunk/permalink/2861420423886153/ Discussion on whether or not mold can penetrate wood barrels or cracks/leaks in barrels from the health concerns of mold that grows on foodoutside.]
==Identifying Mold==
As mentioned above, identifying the species of mold based on what it looks like with the naked eye is not a reliable way to identify it at the species level, and thus not a reliable way to know if the mold growth is safe. It is, however, usually easy to tell the difference between general mold growth and pellicle or yeast growth. Mold tends to look "fuzzy" or "hairy" and often has green, red, black, white, or grey colors, whereas yeast activity or pellicles tend to have evidence of CO2 production (bubbles), and looks look "creamy", "powdery", or "chalky" and is never green, red, or black in color (unless there is material in the beer that is discoloring the pellicle, such as fruit). Mold tends to grow in isolated spots on the surface, while yeast pellicles tend to grow throughout the surface. Sometimes the pellicle is not a solid pellicle, but instead just scattered across the surface in a spotty yet more widely distributed manner compared to mold which would grow in a more isolated area. Protein/carbohydrate coagulation can also be misidentified as mold, however, this also never appears "hairy" or "fuzzy" like mold. We recommend taking a picture through a hand lens when posting an image of what might be mold as this will make it easier to identify. Be sure that the color of the mold/pellicle in the photo is accurate to what it looks like with the naked eye (sometimes cameras make white substances appear more pigmented, which can throw off attempts to identify the organism online). Please make an attempt to identify whether the growth is mold or not on your own before posting in the group (these types of posts clog the stream!). See the images below for examples that should help. Mold can be removed and sent to a [https://www.google.com/search?client=firefox-b-1&ei=Ww08W-fWOabX0gK73K6YBg&q=mold+testing+lab&oq=mold+testing+lab&gs_l=psy-ab.3..0l2j0i20i263k1l2j0l6.127585.128971.0.129112.16.14.0.0.0.0.181.1496.0j12.12.0....0...1c.1.64.psy-ab..4.12.1491...0i67k1j0i131k1j35i39k1j0i131i20i264k1j0i20i264k1.0.5QReSMbR0GU mold testing lab] to possibly be identified as toxic or benign.
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