(a)The class gin. "Gin" is distilled spirits made by original distillation from mash, or by redistillation of distilled spirits, or by mixing neutral spirits, with or over juniper berries and, optionally, with or over other aromatics, or with or over extracts derived from infusions, percolations, or maceration of such materials, and includes mixtures of gin and neutral spirits. It must derive its main characteristic flavor from juniper berries and be bottled at not less than 40 percent alcohol by volume (80° proof). Gin may be aged in oak containers.(b)Distilled gin. Gin made exclusively by original distillation or by redistillation may be further designated as "distilled," "Dry," "London," "Old Tom" or some combination of these four terms.