For the shurb base:

In a bowl, combine the jam and vinegar. Taste the mixture and adjust the balance as needed – Too sweet? Add more vinegar. Too astringent? Add more jam. Keep in mind, the mixture will be strong as it is meant to be diluted with sparkling water.

Optional: strain the mixture through a fine mesh sieve.

Store this base mixture in an airtight container in the fridge for up to a week.

For the shrub sparkler:

Place 3 tablespoons of the shrub base mixture in a glass. Muddle in any fresh herbs or ginger, as desired. Top with 1-1½ cups of sparkling water, to taste. Stir to mix and garnish with fresh herbs or fruit slices.

Optional: you could also add a splash of alcohol, like an aromatic gin, citrus vodka, or limoncello, if desired.