Bittermens Orchard Street Celery Shrub (125 ml)

Bittermens Orchard Street Celery Shrub was partially inspired by a pickle seller in New York, partially inspired by a vintage soda which was made with celery and partially inspired by picklebacks. Sounds pretty cool, right? To make it, they use a shrub, a vinegar-based drink, flavoured with apple and celery and concentrated so it can be used like you would regular cocktail bitters. They suggest trying it with aquavit.