Sourced from the Wikipedia page 'Fudge'...because I live dangerously...
Fudge is a type of Western confectionery which is usually very sweet, and extremely rich. It is made by mixing sugar, butter, and milk and heating it to the soft-ball stage at 240 °F (116 °C), and then beating the mixture while it cools so that it acquires a smooth, creamy consistency. Many variations with other flavourings added are possible.
The components of fudge are very similar to the traditional recipe for tablet, which is noted in The Household Book of Lady Grisell Baillie (1692-1733). The term "fudge" is often used in the United Kingdom for a softer variant of the tablet recipe.
American-style fudge (containing chocolate) is found in a letter written by Emelyn Battersby Hartridge, a student at Vassar College in Poughkeepsie, New York. She wrote that her schoolmate's cousin made fudge in Baltimore, Maryland in 1886 and sold it for 40 cents a pound. Hartridge obtained the fudge recipe, and in 1888, made 30 lb (14 kg) of fudge for the Vassar College Senior Auction. This Vassar fudge recipe became quite popular at the school for years to come.
Word of this popular confection spread to other women's colleges. For example, Wellesley and Smith have their own versions of a fudge recipe dating from the late 19th or early 20th century.
Fudge is a drier variant of fondant.
In forming a fondant, it is not easy to keep all vibrations and seed crystals from causing rapid crystallization to large crystals. Consequently, milkfat and corn syrup are often added. Corn syrup contains glucose, fructose (monosaccharides) and maltose (disaccharide). These sugars interact with the sucrose molecules. They help prevent premature crystallization by inhibiting sucrose crystal contact. The fat also helps inhibit rapid crystallization. Controlling the crystallization of the supersaturated sugar solution is the key to smooth fudge. Initiation of crystals before the desired time will result in fudge with fewer, larger sugar grains. The final texture will have a grainy mouthfeel rather than the smooth texture of high quality fudge.
One of the most important parts is its texture. The temperature is what separates hard caramel from fudge. The higher the peak temperature, the more sugar is dissolved, the more water is evaporated; resulting in a higher sugar to water ratio. Before the availability of cheap and accurate thermometers, cooks would use the ice water test, also known as the cold water test, to determine the saturation of the candy. Fudge is made at the "soft ball" stage which varies by altitude and ambient humidity from 235 °F (113 °C) to 240 °F (116 °C).
Some recipes call for making fudge with prepared marshmallows as the sweetener. This allows the finished confection to use the structure of the marshmallow for support instead of relying on the crystallization of the sucrose.
"Hot fudge" in the United States and Canada is usually considered to be a chocolate product often used as a topping for ice cream in a heated form; it is not necessarily directly connected with the confection known as fudge. Hot fudge is a thick chocolate-flavored syrup (flavored with real or artificial flavorings). It is typically used as a topping for ice cream, particularly sundaes and parfaits. It may also occasionally be topped upon s'mores.