Poitín (also called potcheen, poteen, moonshine or mountain dew) is a drink that has been described as "Irish moonshine whiskey" since 1660. The name comes from the Irish for "little pot," emphasizing its production in homes in — you guessed it — little pots. After the potato was introduced to Ireland in 1589, it was found that potatoes, malt yeast, barley, sugar, and water fermented in a well-seasoned barrel for three weeks and then distilled produced a great-tasting clear baor. Butler's Irish Book (1660) claimed that the drink "enlightened ye heart, casts off melancholy, keeps back old age and breaketh ye wind." Traditionally the drink was distilled over a peat fire and fermented in bog-holes.
In 1661 the English introduced taxes on distilled spirits (tenpence-per-gallon for poitín) that the Irish promptly ignored. In 1760 the English passed a law forbidding private, unlicensed production of distilled liquor, and began enforcing the tax laws already in place. Again, the Irish ignored the English and the country became a nation of criminal distillers and underground alcohol smugglers overnight. Skirmishes broke out and there is mention of local government-enforced distilling operations. In the 1840s poitín production decreased because of the potato crop failure, but Irish newspapers at the end of the 1900s reported that poitín production was alive and well once again.
Historically the drink was also used medicinally: one could bathe in it or rub it on joints to relieve arthritis; it could help a man's virility (when used in moderation); veterinarians used it for lackluster racehorses. In 1730, a doctor claimed that drinking poitín "to the point of intoxication held off old-age, aided digestion, and quickened ye mind." It's been used as dynamite to blow up rocks and also as an ingredient in cakes.
On March 7, 1997, the Irish Revenue Commission repealed the laws prohibiting production of the drink, and now it be produced and sold in Ireland. These days you can buy poitín in many wineries in Ireland: Bunratty Potcheen, "the first since it was banned to be legally produced and bottled in Ireland," contains 40–45% alcohol by volume (80–90 proof) and can be enjoyed "neat as a shot, on the rocks or with a mixer." They describe their brew as "dry and grainy with a delightfully changing aftertaste that sweetens as it develops," and mentions that it is also known as Mountain Dew. McBride's Irish Pub notes that "its aftertaste can have hints of toffee and other flavours," and also mentions Mountain Dew. Knockeen Hills Irish Poteen sells "triple-distilled" poitín in strenghts from 50–90% alcohol by volume (101–180 proof), but only their 101-proof brew is available for sale to the United States.
Though it's now legal to buy poitín, many still opt for their particular traditional home-brewed recipe, which is a closely guarded secret (and also illegal). One way to tell if an illicit poitín is drinkable is to set the liquid aflame: if it burns purple, it "may" be safe to drink; if it burns red it should be "disposed of." Another way of verifying its authenticity is to pour half milk and half poitíin in a tablespoon; if the milk curdles, the drink is no good.
References:
Bunratty Mead & Liqueur Co. Ltd.: http://homepage.tinet.ie/~bunrattywinery/
McBride's Irish Pub: http://www.mcbridesirishpub.com/
Knockeen Hills Irish Poteen: http://www.irish-poteen.com/
Updates:
09 July 2003: New information thanks to CloudStrife.
30 Jan 2004: Revisited...deleted a bunch of pointless hardlinks, and made it XHTML compliant.