My folks were into trying new liqueurs all through my childhood. When they were broke, they made their own from flavorings and cheap vodka. As they finished college and entered the workforce, they could afford more and more interesting liqueurs and other spirits. I've always been fascinated by these strong, strange essences.
A worldwide after-dinner phenomenon, liqueurs range from 23% to 70% alcohol by volume and originated in the 1500's when people felt that crude spirits were too powerful. The point of liqueur production was to mellow the harsh and aggressive flavors of rustic spirits. Because many liqueurs are pretty alcoholic and plenty flavorful, it's hard to imagine what came before. The sugar content must be at least 2.5% by weight.
Almost any kind of plant material can be used to flavor liqueurs; some of which most people seem to think are really nasty. There are three basic types of liqueurs:
Regardless of these contents, there are two methods of liqueur production: distillation and steeping.
In the distillation method, the ingredients are steeped in alcohol for many months. During the steepage, the mixture is stirred or agitated and when done, filtered and distilled. The resulting "aromatic base" is very concentrated.
In the steeping method, fruits and plants are harvested at their peak, individually selected for excellence, and prepared for use (pitted, crushed, stemmed, etc.) before being steeped in alcohol for many months before filtration. After a final tasting and selection process, it is ready to be used as an "infusion".
The blending phase of liqueur production is common to both of the above methods. Combinations of alcohol, sugar syrup, honey, demineralized water, and other agents are added to the aromatic base(s) and/or infusion(s). The wealth of combinations of possible ingredients through this process is the power behind the liqueur paradigm. The source of alcohol for steepage or blending can be anything and varies around the world. It is often distilled fermented sugar, but may also be brandy -- distilled wine.
The final preparation includes allowing the young liqueur to age for a few weeks, final filtration, further aging, and finally, being bottled. Each of the commercial brands (and many hobbyists) keep their recipe a carefully guarded secret.
Quick home liqueur can be made by pureeing 2 lbs. frozen-fresh fruit, 2 cups 100 proof vodka, and 1 cup sugar, in a powerful blender, bottling for 2 to 3 weeks, straining for pulp, and filtering through a coffee filter for the more fine particles. You can experiment with further aging and the addition of flavorings like whole herbs and spices.
Happy Hour Bartending and Cocktails. http://www.happyhour.ca/
Welcome to Winemakeri Inc. http://www.winemakeri.com/Information.htm
#1 Amazing Drink Archive. http://drinks.glowport.com/
Basic Cordials and Liqueurs. Terafan Greydragon. http://www.greydragon.org/library/cordials.html