
Honey is the sweetener bees make from nectar: thick, floral, and more concentrated than sugar syrup.
Two things are in play: the density and the floral flavor. A neutral sweetener of the same weight covers the first and leaves the second out, which in a Bee’s Knees or a hot toddy is what the recipe came for.
Honey syrup
At the ratio the recipe assumes, usually two parts honey to one of hot water. The drink needs its sweetening recalculated against that dilution, because a spoon of syrup is not a spoon of honey.
Agave nectar
It behaves like honey and has almost no flavor of its own — a practical swap where the floral side is beside the point. Where honey is the point, as in a Bee’s Knees, the drink comes out sweet and anonymous.
Honey does not spoil, since there is too little water in it for anything to live. Crystallizing is a different matter and not a fault: stand the jar in warm water and it runs clear again.