We have a bottle of elderflower liqueur, similar to St. Germain’s, and the outside is incredibly sticky. It wasn’t sticky when I bought it, and I’ve actually washed the outside once and it’s still sticky.
We haven’t spilled any on the outside of the bottle - I mean, maybe a drop or two, but the bottle is sticky ALL OVER.
We’ve kept it corked / closed when not in use.
Is the liqueur somehow climbing out of the bottle and evaporating, leaving sugar behind?