Fernet Branca Bitters are made from a grape alcohol base, flavoured with over 40 ingredients, which include absinthe, aloe, anise seed, bay leaves, bitter orange, basil, cardamom, chamomile, cinchona bark, colombus, echinacea, galangal, gentian, liquorice, mushrooms, myrrh, nutmeg, peppermint, rhubarb, rue, saffron, sage, valerian and zedoary.
It is aged in oak casks for a year, and ends up as a dark amber-coloured liquid that is 40% alcohol, sold in 750 ml bottles.
Fernet Branca is a digestif for after meals. It may, however, also be drunk straight up, used in cocktails, or splashed into fizzy mineral water.
The first taste can be quite rough for the uninitiated who balk at its very medicinal taste and smell with a hint of peppermint. It also has a chalky aftertaste. It is generally felt to be too strong for most North Americans who have been known to pronounce the taste as just “vile.” Most North American consumption appears to be done by Italian immigrants, who have acquired the taste for it.
In California, Fernet Branca Bitters is drunk with ginger ale; in Argentina, with Coca Cola (“Fernet con Cola.”)  Italians will have it with an espresso shot on the side.
It is made in Milano, Chiasso (Switzerland) and in Argentina.
 In Argentina, Coca-Cola is made with sugar-cane syrup instead of the high fructose corn syrup that is used in America. The ratio used is 10% Fernet Branca, 90% Coca-Cola, with ice.
An equal amount of Amer Picon, Campari, Punt & Mes, or Unicum.
Some swear by Fernet Branca Bitters as a cure for hangovers (though there is absolutely no science behind the claim.)
There are two versions of where the recipe for Fernet Branca Bitters came from. One is that it was invented by a Maria Scala in 1845, who joined the Branca Family by marrying Stefano Branca. She concocted it, reputedly, as a medication to help women through their monthly periods. The other is that it was invented by Bernardino (aka Bernardo) Branca in 1836.
In any event, Bernardino’s three sons — Giuseppe, Luigi and Stefano Branca — began making the bitters commercially in 1845 in Milan. They called their company “Fratelli Branca”. They first sold the bitters as a medicine in pharmacies. The product was trademarked in 1905. From 1845 to 1913, only women were pictured on the bottle; in 1913, men appeared on the bottle for the first time.
It was first sold in America in 1900, when it was exported directly there in bottles. Since 1932 (some sources say 1934), it has been shipped to America (New York City) in wooden barrels under an arrangement started by a Dr Zempliner and bottled there. Zempliner sold it through advertising its medicinal virtues for decades, until the FDA (Food and Drug Administration) clamped down on him and said that if he was going to advertise it as a medicine, it had to be regulated like a medicine. He stopped the importing business in 1978. The importing was restarted in 1998 by a man named Aurelien de Seze, in association with the Branca family. The company had kept ownership of the warehouse in Tribeca, New York, in the intervening time.
The company is still owned by the Branca family. In 1998, the chairman was Count Niccolo Branca (the family has become ennobled.)
Bernardino Branca built the Villa Giulia on Lago Maggiore. By 1878, his son Giuseppe (died 1904) was a “Cavalier” in societal rank, and married to a woman named Giulia. He reacquired the family home on Lago Maggiore, which had been sold to a General Müller, and improved the home.
Marra, Andrew. A bitter drink goes better with Coke: How the Fernet and Coke became Argentina’s favorite cocktail. Cox News Service. 6 December 2007.