In a medium-large bowl, mash fruit (or run through a food processor). Add sugar and vinegar. Mix well then cover with a clean tea towel. Allow the mixture stay out for at least 24 hours and up to two days.
Strain the fruit through a fine mesh sieve into a clean bowl or pitcher. Press down on the fruit to remove as much juice as possible. You can keep the mixture clear or press further to add some of the pulp (your choice).
Add vanilla then taste. Add more vinegar if you’d like. Traditional shrubs contained a lot of vinegar.
Pour into a clean jar with a lid and keep in the refrigerator until using.
The shrub will last several months, though you’ll probably use it up sooner!