This is my first post in a series recapping answers that I’ve given to various cocktail questions on Quora. This answer covers some liqueurs most people may not be familiar with that are useful for making interesting cocktails.
Here’s a list in roughly the order I would buy them:
Maraschino Liqueur – This is a staple in many classic cocktails. Luxardo is the standard brand, and comes in a fairly iconic bottle with a wicker wrapping. Sweet with a floral aromatic scent.
Campari – Needed to make the Negroni, Americano, Boulevardier, and a variety of other classic cocktails. It starts sweet and then becomes quite bitter, but the bitterness can be cut by a variety of other ingredients, especially orange flavors. I’ve heard it said that you need to drink Campari three times before you’ll like it, but it’s great once you get over that initial hurdle.
Chartreuse – This is an herbal liquer made by French monks. It is sweet, but not overly so, and has an excellent herbal flavor. There are both yellow (80 proof) and green (110 proof) varieties, with the green having a stronger flavor. A little on the expensive side at roughly $50 a bottle, but worth it. One of my favorite cocktails is a variant of the Sidecar called the Champs de Elysees, which uses yellow chartreuse in addition to the normal brandy, cointreau, and lemon juice. The Last Word is another popular cocktail that uses chartreuse. If you can only buy one thing on this list, buy chartreuse (probably the yellow, as the green can be dangerous).
Creme de Violette – Tastes like you might guess from the name. A key ingredient in classic cocktails such as the Aviation and the Blue Moon. Not as useful as the above three liqueurs in my opinion, but nice to have on hand.
St. Germain – An elderflower liqueur that has become popular in the last five years. Has a pleasantly sweet taste that pairs well with almost anything. I think it’s too popular at the moment, which is why I don’t have it higher on the list.
Aperol – Related to Campari (above), but sweeter and not as bitter. Aperol is often used as a substitute for Campari in variants of the Negroni, for example, and may be even be mixed with Campari to offset some of Campari’s stronger flavors.
Fernet – An italian amaro with a very unique and complex flavor that is definitely an acquired taste. Cocktail snobs order this straight in bars, but there are many great cocktail options. You can see an interesting list here: Cocktails: What’s the best cocktail containing Fernet Branca?. Fernet Branca is the most common variety, but Luxardo also makes a version that’s available in the US.
There are a bunch more that I haven’t listed here for brevity: Benedictine, Cynar, Galliano, Ramazzotti, Pimms, etc.
Don’t forget to also buy orange bitters, if you don’t have them.