What are they?
Hops are the cone-like flowers of a climbing vine that is native to the temperate regions of North America, Europe and Asia. The species has separate male and female plants and only the female vines produce the cones. The vines will climb 20 ft or more up any available support and are commonly trained onto strings or wires when grown commercially. The leaves resemble grape leaves and the cones vaguely resemble pine cones in shape but are light green, thin and papery. At the base of the petals are the yellow lupulin glands which contain the essential oils and resins that are so prized by brewers
Hops have been cultivated for use in brewing for over 1000 years. The earliest known cultivation was in Central Europe, and by the early 1500s, cultivation had spread to Western Europe and Great Britain. At the turn of the century, about one dozen varieties of hop were being used for brewing; today, there are over one hundred. The focus of breeding programs has been to maintain desirable characteristics, while improving yield and disease resistance.