Empirical Spirits The Plum, I Suppose

The headline says most of what you need to know, but if you're really curious...

The description by "The Chaps" does a good job of characterising this except for one major (imho) omission: a very prominent sour note. (I regret not starting, as recommended, with the Helena, because I have no idea whether the sourness is inherent to the koji or the botanicals, fwiw.)

This sour note makes it a non-starter as the star of the show; I can't imagine any version of a martini made with this that doesn't end in a spit-take.

But! Having committed to £40's worth, I experimented until I found something that worked, and paired with properly sweet partners, it can work well. Great with cherry juice, weird but nice with pineapple. In the end, I drank most of it in a Negroni-style cocktail with a v. fruity sweet vermouth, where it shined and made a familiar favourite newly interesting. If you have a liqueur that you love for the flavour but find overly sweet, this could be just the thing.

I don't know if I'll ever buy this again, but I'm happy to recommend it to novelty-seekers and aspiring mixologists who are looking to flex. Everyone else: caveat emptor.