A liqueur is a spirit drink with at least 100 grams per litre of sugar and a minimum alcoholic strength of 15% ABV, with some exceptions.  

Liqueurs, cordials or spirits, are flavoured with natural or artificial ingredients. These ingredients include fruits, herbs, spices, nuts, flowers, and other botanicals. They typically have a sweet and often syrupy taste due to adding sugar or another sweetener.  

Some well-known examples of liqueurs include Grand Marnier (orange-flavoured liqueur), Amaretto (almond-flavoured liqueur), Baileys Irish Cream (a cream-based liqueur), and Kahlúa (a coffee-flavoured liqueur). These liqueurs have a distinctive taste profile, making them popular choices for cocktails and mixed drinks. 

The creation of liqueurs can be traced back to ancient civilisation when liqueurs were, like many spirits, developed for medicinal purposes.    

Development continued in the Middle Ages with monks cultivating vast herb gardens and experimenting with various ingredients to perfect their liqueur-making techniques.   

The turning point for the industry was during the Renaissance, which saw new advancements in distillation techniques. And as European explorers ventured to distant lands, they brought back exotic ingredients and spices, enriching the available liqueur options.

The Industrial Revolution introduced mass production techniques, making liqueurs more accessible to the general public and liqueurs transitioned from being crafted in small batches for personal use to being produced on a larger scale for commercial purposes.  

The mid-20th century saw an explosion of brightly coloured liqueurs, such as blue curacao, revitalising a cocktail culture that Prohibition had decimated. There was also further technological progress with innovations like Baileys in 1974, the first shelf-stable Irish whiskey and cream liqueur.  

Owing hugely to cocktail culture, the world of liqueurs and other spirited drinks has developed from medicinal remedies to bar staples that offer a galaxy of fruits, spices, herbs and different exotic flavours. 

In the United States, cordials are sweet, low-alcohol liqueurs and the two terms are often used interchangeably. However, on the other side of the pond, cordial has a different meaning; it typically refers to a non-alcoholic syrup, like Rose's Lime Juice Cordial. Cordials have more complexity and intensity in flavours with sugar and acidity (resulting in sweet and sour tastes). 

There three basic methods employed for extracting flavours in liqueur production are percolation, maceration, and distillation. The first two methods are cold methods where heat is not applied and the third is akin to the production of distilled gin. The following describes the basic principles however technology and food science advancements continue to improve quality and efficiency.

• Like brewing tea, maceration involves steeping fruits or flavouring agents in spirits that are sensitive to heat.  
• The fruits or other flavouring agent(s) are allowed to steep in spirits (maceration) or water (infusion) until the desired flavours, aromatics and colour have been extracted.  
• This slow process can take anywhere from one day to a year, as some materials may lose flavour or characteristics if heated.

• Much like coffee percolation, this method uses a large tank to extract flavours.  
• This method also known as ‘brewing’ is usually for plant-based flavourings such as herbs.  
• The raw material is in a basket or cloth bags, and the spirits are repeatedly pumped over the material (for weeks to months) or boiled, allowing vapours to rise. 
• Like maceration, the remaining spirit-soaked flavouring agent may be distilled, and the distillate added to the percolated spirit.  
• Ageing before bottling is optional but not common.

• The distillation method is similar to distilled gin production. 
• The flavouring agents are steeped in spirit for a few hours and then distilled in a small to medium copper pot still.  
• This method is for materials that are less heat sensitive and benefit from a faster extraction such as spices, roots, citrus peels and dried herbs.  
• As per most distillation methods, the heads and tails are discarded and only the heart distillate is used for the final product.  
• To preserve more delicate flavours from materials such as roses, violet and mint, a partial vacuum still may be adopted to reduce distillation temperature and the spirit could be swapped for water.  
• A high-proof, heavily flavoured, colourless distillate is produced and reduced before bottling by adding syrup (sugar and demineralised water) and optional food-safe colourings of any hue.

Liqueurs hail from various regions worldwide, each with its own unique traditions and flavours. Some famous examples include limoncello from Italy, Chambord from France, and Kahlúa from Mexico.

• Monastic & Herbal Liqueurs: These are flavoured with a combination of herbs and spices, resulting in a complex flavour profile.  
• Generic Liqueurs: This is the largest category of liqueurs, encompassing flavours commonly found in a bartender's collection. Any liqueur with the prefix ‘crème de’ in its name denotes that the minimum sugar content is 250gm per litre according to EU regulations. Liqueur examples include crème de menthe (mint), creme de fraise (strawberry) and crème de framboise (raspberry), amaretto, maraschino, and triple sec. Whilst the flavour profiles of each liqueur across brands can be similar, the quality offered can vary substantially between brands. 
• Proprietary Liqueurs: This refers to liqueurs made to a closely guarded recipe solely owned by the producer; other brands cannot replicate them. Most of these liqueurs would, in most cases, have centuries of tradition behind them. 
• Cream Liqueurs: These liqueurs contain dairy products, like Baileys or Dutch Advocaats (egg custard liqueurs). This category was pioneered by Baileys in the 1970s when Gilbeys of Ireland created the first shelf-stable product which will not deteriorate opened or unopened, refrigerated or not for over two years (when kept out of direct sunlight). Today, Baileys remains the best-selling liqueur in the world.

While some liqueurs involve intricate recipes and lengthy infusions, simple homemade liqueurs that require minimal effort and a few key ingredients. It's also a great way to use up seasonal ingredients.

Discover liqueur innovations, skills masterclasses and more when you join the Diageo Bar Academy.