A Shrub (also known as “Drinking Vinegar”) is a concentrated syrup made of three ingredients: fruit, sugar, and vinegar. Historically used to preserve fruit before refrigeration, shrubs are now popular as a tart, sophisticated base for sodas and cocktails. You can use shrubs to zest up mocktails and cocktails, and add a little zing to your morning routine with a favorite shrub diluted in warm water as an afternoon pick-me-up when mixed with sparkling water.