Unsweetened, distilled, alcoholic beverages that have an alcohol content of at least 20% ABV are called spirits. Spirits are produced by the distillation of a fermented base product. Distilling concentrates the alcohol and eliminates some of the congeners. For the most common distilled beverages, such as whiskey and vodka, the alcohol content is around 40%. Spirits can be added to wines to create fortified wines, such as port and sherry.