Probably the oldest of all high-strength alcoholic beverages they were originally the preserve of monks who produced them primarily for medicinal purposes. The first record of a liqueur belongs to Kummel in 1575; made with caraway seeds as an aid to digestion. Some liqueurs sold today still retain their ancient heritage and their recipes are often closely guarded secrets. In some instances they are not even written down but passed on by word of mouth from one generation to the next, while with others, the holders of these secrets refuse to fly on the same plane as one another!

It is important to make a distinction between liqueurs and spirits even if this distinction can on occasion become somewhat blurred. A liqueur is a spirit that has been sweetened and flavoured, whereas natural sugars are fermented into alcohol and subsequently distilled to make a spirit.

In order to make a liqueur, one needs something with which to sweeten the spirit-generally sugar or honey-and something soluble with which to flavour it. The character of a liqueur will always come from these flavouring agents rather than from the base spirit. Hence, the derivation of the word liqueur from the Latin liquefacere meaning to dissolve.

According to a 1989 European law liqueurs must have a minimum of 15 % alcohol and a minimum 100 grams of sugar per litre (250g/litre for crèmes de fruits). Additionally, they can be made with fruits, natural flavourings, naturally synthesised aromas and flavourings-where the fruit molecule has been recreated. However, the latter is forbidden with blackcurrant, cherry, raspberry, blueberry, citrus fruit, pineapple and plant liqueurs-such as mint-where natural flavourings must be used.

WHAT ARE LIQUEURS MADE FROM?
From their historical development to modern day proprietary brands most liqueurs and alcoholic cordials have an existing spirit as their base. In descending order of popularity these are derived from:

• NEUTRAL SPIRIT,  Grain, fruit or molasses.

• BRANDY, Grape wine or fruit wine.

• RUM, Sugar cane juice or molasses.

• WINE, Grape or fruit wine to give softer flavour.

• WHISKY, Famously Scottish or Irish.

• There is diverse range of liqueurs, which can be broadly categorised as follows:

• FRUIT e.g. cherry and apricot brandy.

N.B. Despite their nomenclature these are not actually brandies at all ; they are by definition liqueurs. The real cherry brandy is Eau de Vie de Kirsch.

• 
  CRÈMES, Notably Crème de Cassis.

• CITRUS, e.g. triple sec and curaçao.

• MIXED & SINGLE HERB OR FLOWER (PETALS, SEEDS OR ROOTS), e.g. caraway, mint, aniseed, violet, rose and bitters, which have more than 100g / litre of sugar and anise (e.g. Sambuca).

• BEANS & KERNELS e.g. cocoa beans, coffee beans, vanilla pods, nuts.

• CREAMS, e.g. based on Irish whiskey, brandy, toffee, peppermint.

• MISTELLES, Fresh fruit juice with its fruit distillate and a minimum of 100g/litre sugar if classified as a liqueur ; the addition of high-strength alcohol prevents the juice from fermenting whilst stabilising the character and natural sugars of the fruit. Containing no wine, yet sometimes erroneously referred to as wine spirit liqueurs! e.g. Pineau de Charentes from Cognac, Floc de Gascogne from Armagnac, Pommeau de Normandie from Calvados and Ratafias—which nowadays refers to French grape-based mistilles; historically were drunk at the ratification of treaties.

WHAT CAN BE ON THE LABEL?
BRAND NAMES: Many of the most famous liqueurs stand on their own as brands ; others include the name of the proprietary spirits they are based on. These should always guarantee the user of quality.

PRODUCER NAMES: Many of the world’s biggest producers have big ranges of flavours covering all types of liqueur. To them their name is the most important and the flavour is generic.

FLAVOURINGS: Here the liqueur world is confusing. One man’s violet could be similar to another’s Parfait d’Amour, both of which often contain vanilla, or rose petal. Oriental melon liqueurs may use the same ingredient but call themselves by what the fruit is known as in the local language. However, in general the predominant flavour will be indicated by its name or a picture of the fruit, flower or spice.

COUNTRY OF ORIGIN: The traditions and palate of the indigenous population can also have an influence on the flavour.  This is most evident with regard to levels of sweetness with some countries preferring sweeter or drier liqueurs to others.

HOW ARE LIQUEURS MADE?
Firstly one selects the base (often supplied by spirit rectifier), for its neutrality or inherent flavour, and secondly one collects the flavouring matter. These materials are often from all over the world, selected for pungency, colour and depth of aroma.

The base and flavourings are then combined and the sugar is added.

COLD MACERATION: This can take a long time-in fact as long as a year in some cases-and is the only method that can be used in the case of some aromatic plants to truly retain their character and colour.

HOT INFUSION: A method not dissimilar to a coffee percolator whereby the crushed flavouring agent is placed in a filter and hot liquid poured through it. Unlike the coffee machine, however, it works on a cycle and the liquid is passed and re-passed through the filter.

DISTILLATION: The material is directly distilled in a pot still with its alcohol base, or the vapours of the distillate are passed through filters containing the crushed flavouring matter.

MECHANICAL PRESSURE: The matter, such as fruit peel, is milled and pressed to extract the flavour. Sugar in syrup form will be added post distillation to the spirit, or combined with the drawn-off macerate and then added to the spirit. In many cases, such as with cream liqueurs, this may involve the use of a stabilising agent at the same time.
The product then rests to encourage harmonisation. Often the marrying time is quite short, but some liqueurs are aged in tank or cask to allow the deepening of the flavour or the influence of oak.

It should be noted that curaçao originally meant a liqueur made from oranges from the island of Curaçao in the Dutch West Indies. But today it tends to be used generically to describe any liqueur whose predominant flavour is derived from citrus peel. Curaçaos are initially clear but may be coloured (hence the availability of orange and blue styles), they may have an alcoholic content from 15–40 % and may have a sugar content from 100–300g/litre. The huge popularity of curaçao is helped as it is an essential ingredient in some of the world’s favourite cocktails such as the Margarita.