
Hazelnut liqueur is a sweetened spirit flavoured with roasted hazelnuts, typically backed by vanilla, cocoa or coffee notes.
Syrupy and rounded on the palate, finishing long and sweet on roasted-nut warmth, with vanilla, cocoa and a touch of coffee threaded through.
Bartenders pour it as a sweetening, aromatic modifier — stirred or shaken into the build in small measures where its viscosity and roasted-nut aroma lend body and warmth. It contributes little strength, so the base spirit carries the alcohol.
Hard to replace where the drink is meant to taste of hazelnut, since the roasted-nut aroma cannot be reproduced by almond or coffee notes. As a small aromatic accent another sweet nut liqueur can stand in, with sweetness rebalanced by sugar syrup and the minor alcohol made up by the base spirit.
Amaretto / almond liqueur
Amaretto is flavoured with almond or apricot-kernel character and reads as marzipan-like, whereas hazelnut liqueur carries a roasted, earthier nut profile. They are different nut aromatics and do not substitute for one another in aroma.
The hazelnut character comes from roasting or toasting the nuts and then either macerating them in a neutral spirit or distilling them into an infusion or distillate. Heavily sweetened — a leading example runs to roughly 40% sugar by weight — it is usually amber-coloured, often with added caramel colouring, and rounded out with vanilla, cocoa and coffee.
Commercial bottles keep indefinitely unopened and for a long time once opened; house-made infusions are perishable and best used within a couple of months.
The style is strongly associated with the Piedmont region of northern Italy, a hazelnut-growing area.