They are used primarily as a flavoring and stability agent in beer, to which they impart a bitter, tangy flavor, though hops are also used for various purposes in other beverages and herbal medicine. In the Middle Ages beers tended to be of a very low alcohol content and were commonly consumed as a safer alternative to untreated water. Each village tended to have one or more small breweries with a barley field and a hop garden in close vicinity. Early documents include mention of a hop garden in the will of Charlemagne's father, Pepin III. However, the first documented use of hops in beer as a flavoring agent is from the 11th century. Before this period, brewers used a wide variety of bitter herbs and flowers, including dandelion, burdock root, marigold, horehound (the German name for horehound means "mountain hops"), ground ivy, and heather. Hops are used extensively in brewing for their antibacterial effect that favors the activity of brewer's yeast over less desirable microorganisms and for many purported benefits, including balancing the sweetness of the malt with bitterness, contributing a variety of desirable flavors and aromas. Historically, traditional herb combinations for ales were believed to have been abandoned when ales made with hops were noticed to be less prone to spoilage.