Liqueurs originate from as far back as the 13th Century although the modern usage of the term 'liqueur' only came into use in the 16th Century.
A liqueur is made by combining distilled spirits with a variety of flavourings and sweetening to various degrees. Liqueurs are, by definition, sweet alcohols, and must contain at least 2.5 % sugar by weight so as to endow them with the name of being a 'liqueur'. Most, however, have between 17% and 35% sugar weight per volume alcohol (some even have as much as 55 %).
There are three main ways to make liqueurs:
Infusion/Maceration: this method is used to extract fruit flavours and flavours from seeds and flowers;
Percolation: used to obtain flavouring from leaves and herbs;
Distillation: used to extract flavour from seeds and flowers.
Liqueurs are normally consumed as aperitifs, as 'digestifs, as ingredients in classic cocktails or as a flavour enhancement to foods when cooking - normally for desserts and puddings.