Step 1

Gently mash berries in a medium bowl with a fork. Transfer to jar, add sugar, and stir to combine. Seal jar and let fruit mixture sit at room temperature, shaking a couple of times, until berries are very soft and falling apart and sugar is at least mostly dissolved, about 1 day (mixture should look very juicy).

Step 2

Strain fruit mixture through a fine-mesh sieve (line sieve with a layer of cheesecloth if you want to catch every bit of seed and fruit pulp) into a medium bowl; discard fruit. Scrape any undissolved sugar left in jar into bowl.

Step 3

Add vinegar to syrup and stir to combine. Taste shrub and add more sugar or vinegar to your liking—it should taste both sweet and sharp but not overpowering in either direction (keep in mind the flavors will meld as the shrub ages). Pour shrub into a clean jar; cover with lid and chill until flavors come together and mellow, at least 1 week.Do ahead: Shrub can be made 6 months ahead. Keep chilled.

Step 4

For a refreshing nonalcoholic drink, pour 2 Tbsp. shrub into a glass filled with ice and top off with club soda; stir gently to combine. Garnish with berries and/or herbs if desired.