Irish Cream is a mixture of whiskey, cream, and sugar. It is sold pre-blended and nearly always uses Irish whiskey as its base. It is also a flavor for a number of other sweets, such as ice cream. Baileys Irish cream is by far the most popular brand on the market.
This beverage began its rise to popularity in the 1970s with its official creation by R.J. Bailey & Company in Ireland. The drink was formulated to appeal to a wide range of drinkers, particularly an American audience. Most Irish cream smells of hazelnuts or sweet almonds, and it is very sweet to taste. By 2003, Baileys had become the top selling liqueur worldwide, and its popularity has only continued to increase. In the same year, the company released a less-alcoholic version called Baileys Glide, which is sold prepackaged in small bottles.
Because of the presence of dairy, Irish cream will curdle and coagulate when combined with any sort of acid. In fact, there was for some time a persistent legend that drinking this beverage with tonic water could kill you. This is of course patently false, but there are many who still believe it.
Though not deadly, the coagulating effect of Irish cream and an acid makes it ideal for a number of prank drinks, most famously the Cement Mixer. A Cement Mixer consists of giving a person a shot of lemon juice or some other highly-acid juice to hold in their mouth, then giving them a shot of Irish cream to drink them down together. When the cream meets the acid, it forms a thick substance in the mouth that is difficult to swallow.
Many people also make their own Irish cream by starting with a good Irish whiskey, placing it on a double-boiler, mixing in flavoring such as chocolate, adding sweet-and-condensed milk, and then stirring in a large amount of cream and coffee flavoring if desired. Once made, the concoction is bottled and refrigerated for a few weeks, at which point it is ready to enjoy.