Place the shredded apple and ginger in a jar with a tightly fitting lid.

Combine the vinegar, lemon juice, water, and sweetener in a saucepan over medium heat. Bring to a simmer and cook until the sweetener dissolves.

Remove from heat, and allow to cool to room temperature.

Pour over the apple ginger mixture. Refrigerate for 5 days.

Strain through a fine metal sieve and keep for up to 1 week in the refrigerator, covered.

To serve, add 2 tablespoons of the shrub syrup to 8 ounces of sparkling water, soda water, or prosecco.