Legal in the United States since 2010, moonshine is defined as "clear, unaged whiskey", typically made with corn mash as its main ingredient. Liquor-control laws in the United States always applied to moonshine, with efforts accelerated during the total ban on alcohol production mandated under the 18th Amendment of the Constitution. Since its repeal, and moonshine's recent legalization, they focus on evasion of revenue taxation on spiritous or intoxicating liquors. Applicable laws are enforced by the Bureau of Alcohol, Tobacco, Firearms and Explosives of the US Department of Justice, once known colloquially as "revenooers".
Moonshine is known by many nicknames, including white liquor, white lightning, mountain dew, choop, hooch, homebrew, ‘’’shinney’’’, white whiskey, and mash liquor.
The word "moonshine" is believed to be derived from the term "moonrakers" used for early English smugglers and the clandestine nature of the operations of the illegal Appalachian distillers who produced and distributed whiskey.
When illegal in the United States, moonshine distillation was done at night to avoid discovery. Moonshine was especially important to the Appalachian area. This white whiskey most likely entered the Appalachian region in the late 18th century to early 1800s. Scots-Irish immigrants from the province of Ulster in the north of Ireland brought their recipe for uisce beatha, Gaelic for "water of life". The settlers made their whiskey without aging it, and this is the same recipe that became traditional in the Appalachian area.
In the early 20th century, moonshine became a key source of income for many Appalachian residents like Marvin "Popcorn" Sutton, since the limited road network made it difficult and expensive to transport corn crops. As a study of farmers in Cocke County, Tennessee, observes: "One could transport much more value in corn if it was first converted to whiskey. One horse could haul ten times more value on its back in whiskey than in corn." Moonshiners in Harlan County, Kentucky, like Maggie Bailey, made the whiskey to sell in order to provide for their families. Others, like Amos Owens, from Rutherford County, North Carolina and "Popcorn" Sutton from Maggie Valley, North Carolina sold moonshine to nearby areas.
Marvin "Popcorn" Sutton's life was covered in a documentary on the Discovery Channel called "Moonshiners". The legendary bootlegger once said that the malt (a combination of corn, barley, rye) is what makes the basic moonshine recipe work. In modern usage, the term "moonshine" ordinarily implies that the liquor is produced illegally; however, the term has also been used on the labels of some legal products as a way of marketing them as providing a similar drinking experience as found with illegal liquor.
Poorly produced moonshine can be contaminated, mainly from materials used in the construction of the still. Stills employing automotive radiators as condensers are particularly dangerous; in some cases, glycol, products from antifreeze, can appear as well. Radiators used as condensers also may contain lead at the connections to the plumbing. These methods often resulted in blindness or lead poisoning for those consuming tainted liquor. This was an issue during Prohibition when many died from ingesting unhealthy substances. Consumption of lead-tainted moonshine is an important risk factor for saturnine gout, which is a very painful but treatable medical condition that damages the kidneys and joints.