Mold

(In progress)

Mold is a type of fungus. It appears on surfaces as fuzzy or hairy patches and may be colored as white, gray, green, red, or black.

Wild mold growth resulting from contamination is generally a health hazard because it can produce allergens and toxins, some of which are carcinogenic.

Therefore the entire batch of beer, wine, etc. with mold growth on it should be carefully dumped.

The one exception to this is when a domesticated mold culture is used intentionally, such as with Sake or rice wine.

Prevention

Mold can generally be prevented in beer by oxygen avoidance and pitching healthy yeast. In wine, pitching healthy yeast, punching down fruit, sulfite usage, and stabilization can all help prevent mold growth. Reducing open air exposure goes a long way toward preventing mold spores from getting in.

See Contamination for more info.

Myths

Myth: The beverage will be OK if you just scrape off the mold patches.
Truth: Mold is by definition filamentous. It sends out hyphae, or "roots" in laymen's terms, and it can secrete allergens, toxins, and carcinogens that would be impossible to separate from the liquid/culture. Carcinogens wouldn't get you sick immediately, so you wouldn't even necessarily know you're ingesting them.

Myth: Small amounts of mold may be OK.
Truth: We generally recommend avoiding the health risk, as does the USDA: "Microbiologists recommend against scooping out the mold and using the remaining [soft food]."

It's impossible for us to quantify how much mycotoxin or allergens may be present. Some people have life-threatening reactions to penicillin for example, which could trigger with a very small amount.

There are a wide variety of possible toxins and they have negative health impacts even in small amounts.

Home brewers have experienced serious illness from brewing with moldy grain.

See also

• http://www.milkthefunk.com/wiki/Mold