
Anisette is a colorless, sweet anise-flavored liqueur, popular around the Mediterranean.
Anise is the flavor and sugar is the variable: the dry bottles in this family need syrup added, and the sweet ones do not. Strength moves too, and the louche is the tell that the anise is real.
Pastis is made much the same way and tastes comparable, but it pairs anise with licorice root, where anise liqueur leads on anise alone. Pastis reads sweeter and rounder in the glass, louches harder with water, and stands near 45% against anisette’s 25% — the same measure carries far more alcohol.
Sambuca is essentially the Italian anise liqueur, with a high minimum sugar content of around 350 g/l, which makes it noticeably sweeter. Substitute it and the drink needs its syrup cut.
Absinthe is distilled and unsweetened, built on wormwood, green anise and fennel; anisette is sweetened and led by anise. Absinthe is also far stronger, so a bar-spoon of it does what a full measure of anisette does not.
It keeps for years unopened and for a long time after, but anethole comes out of solution in the cold and clouds the bottle. That is reversible and harmless. What is not reversible is sun damage, so keep it off a bright shelf.