With its pretty pink color and sweet-and-sour flavor, this simple shrub is a delicious and simple way to use up all the rhubarb in your garden. Mint, cardamom, and ginger are all nice additions to the basic recipe, if you’d like to liven it up a bit.
Place the rhubarb into a quart-sized mason jar. Cover with vinegar, and then seal tightly. Let it sit, away from direct light and heat, for 5 days. Shake the jar daily.
Strain the rhubarb vinegar through a fine-mesh sieve into a small saucepan. Stir in the sugar, and set the saucepan on the stove over medium-high heat. Warm the vinegar and sugar together until the sugar completely dissolves, forming a fine syrup. Transfer the shrub syrup to a bottle.
To serve, mix one tablespoon of the syrup into 8 to 12 ounces of sparkling water, tap water, or mix into a cocktail.