Due in large part to the cocktail renaissance of the last few years, shrubs have come screaming into the present from an era when the United States were but a gleam in the Founders' eyes. Shrubs are an old method of preservation, and when done properly, you can enjoy the fruits of summer's labors in the dead of winter. They're used in cocktails in a similar fashion to syrups. The component parts are a subject, a sweetener and vinegar. We'll break down how to do a basic shrub and what the rules are, so that you can break them when you make your own. There's a bit of science involved behind the scenes, and the whole process is based in fermentation, but don't let that shake you. Making a shrub is as easy as discovering penicillin, when you get down to it.