A glass of clear moonshine may look identical to water, but this illicit alcoholic beverage is infamous for its potency — and for the peril associated with drinking it.
What is moonshine? Broadly, moonshine is any type of distilled liquor that’s manufactured without government oversight, though some argue that moonshine can be labeled as such only when it is made with certain ingredients or comes from specific geographic regions.
People all over the world make and drink moonshine, particularly in places where alcohol is illegal or where legal alcohol is prohibitively expensive or hard to get. But producing moonshine is a tricky chemical process. When it’s unregulated, manufacturers’ mistakes, ignorance or shortcuts can yield a highly toxic product.
So, how does that happen, and how can you tell if a glass of moonshine is safe?
Alcohol in moonshine and other intoxicating drinks comes from fruits or grains that are fermented — that is, they are exposed to yeasts or bacteria that convert sugar molecules to carbon dioxide and alcohol.
Ingredients for moonshine vary widely depending on what’s available. In the early 20th century, American moonshiners typically made their brews from corn mash. But moonshine is also made from grapes, plums or apricots (Armenia), barley (Egypt), palm tree sap (Myanmar), bananas (Uganda) and cashew fruit (India), said Kevin Kosar, author of “Moonshine: A Global History” (Reaktion Books, 2017).
“It’s just basic chemistry. If you can tease sugar out of something, you’re on your way to making a drink.
Fermentation produces two forms of alcohol: ethanol and methanol, which is also known as wood alcohol. Though ethanol is generally considered safe for drinking, both ethanol and methanol suppress the central nervous system and inhibit brain function. Consuming too much alcohol — even the “safe” kind — can cause alcohol poisoning, affecting heart rate and breathing and even leading to coma and death, according to the Mayo Clinic.
Methanol is far more dangerous than ethanol, said Anne Andrews, a professor of psychiatry, chemistry and biochemistry at the University of California, Los Angeles. In the human body, methanol is converted to formaldehyde — the same substance in embalming fluid — and then to formic acid, which is highly toxic to cells.
“It interferes with their mitochondria, and actually causes cells to suffocate,” Andrews said.
Regulated alcohol production is carefully monitored. Products are rigorously tested to ensure that methanol is separated from the beverage and that the amount of ethanol does not exceed legal limits, Andrews said. But for moonshine makers, there are no universal guidelines or enforced safety checks. Moonshine can therefore be much more potent than legal beverages, and it’s all too easy for a batch of moonshine to turn toxic.
If fermentation vats are unsterilized, that can promote the growth of bacteria that pump out methanol, resulting in a higher methanol concentration than expected, Andrews explained. And if moonshiners aren’t cultivating microbial communities for fermenting the moonshine — “inoculating” it with species that don’t produce methanol — unexpected shifts in environmental bacteria can also generate a methanol spike.
“That moonshine could have been safe for years,” Andrews said. “But then something changes in the environment, affecting local microbes that are doing the fermentation. Now there’s a higher concentration of methanol, and the person making it would never know.”
If there’s already methanol in moonshine from fermentation, distilling the batch makes things worse, Andrews said. Ethanol has a lower boiling point than methanol, so distillation — selectively removing compounds through boiling and condensation — boils out the ethanol and concentrates the methanol, she said.
Poison for profit
In some cases, greed is the cause of moonshine’s toxicity. Unscrupulous manufacturers that want to increase the volume of their moonshine either don’t remove methanol or add a cheap, toxic alcohol like isopropyl, which is found in rubbing alcohol, said Kosar. Though this tactic may boost profits, it significantly raises the risk that the drink will be poisonous.
“With alarming regularity, there are stories — often coming from parts of Asia — where people go out and buy illicit alcohol, they have a party, and then hours into the party, people just start dropping and having convulsions,” Kosar said.
Drinking alcohol with high levels of methanol can also lead to blindness: Methanol caused 130 deaths and 22 cases of blindness in just six months during Prohibition, according to a 1922 article in The New York Times that cited a report by the U.S. National Committee for the Prevention of Blindness.
Even when moonshine doesn’t contain toxic levels of methanol, it’s impossible to tell how strong it is — an uncertainty that could lead to accidental alcohol poisoning The best way for drinkers to stay safe is to give illicit alcohol a wide berth, Kosar said..
“Unless you’re a close friend of the person producing the moonshine and have absolute trust in their competence to produce it, don’t drink it,” he warned.