The one rule that separates a liqueur from a liquor is added sugar. Liqueurs are spirits bottled with added flavors from fruits, herbs, or nuts plus sugar, usually 15 to 55 percent alcohol, and that sugar changes the viscosity, density, and mouthfeel of the liquid. The labels mislead constantly. A chocolate cream liqueur like Cadbury or Mozart contains real dairy, but the French crème in crème de cacao means no dairy at all: under European law it marks a liqueur with at least 250 grams of sugar per liter, close to 200 grams in a single bottle. Dark crème de cacao gets its color from macerating roasted cacao beans, while the white version is distilled so only light aroma molecules carry over.

The episode tours the back bar: orange liqueurs like Cointreau, Grand Marnier, triple sec, and curaçao, whose limonene-rich peel oils cut through the sugar; regional fruits like South Africa’s Amarula, Malta’s prickly pear Bajtra, and Cambodia’s Sambai; and the dividing line between sweet fruit liqueurs and dry fruit brandies like kirsch and slivovitz. Monastic herbal blends were digestifs first: Jägermeister uses 56 herbs, Centerbe claims a hundred, Chartreuse 130, and Benedictine 27. Anise splits too, with sweet sambuca and pastis on one side and unsweetened absinthe, ouzo, and arak on the other.

• Amaretto is often made from apricot, peach, or cherry kernels, whose benzaldehyde tastes like almond.
• Italy’s nocino is made from unripe green walnuts harvested early in summer.
• Krupnik blends honey with up to 50 herbs.
• Drambuie softens Scotch with heather honey and herbs, and Irish Mist blends Irish whiskey with heather and clover honey.
• Sweetening whiskey began as a practical way to make rough early spirits drinkable.