is an American hop that originated in 1983 as a cross between a tetraploid German hallertauer mittelfrueh and genetic diploid male material with Cascade and German aroma-hop parentage. As such, it can be considered a half-sister to Liberty. See cascade (hop), german hops, hallertauer mittelfrueh (hop), and liberty (hop). Being a triploid, Crystal produces nearly seedless cones even when grown in the presence of fertile diploid males. Crystal is adapted to the major US hop growing areas in Oregon and Washington. It matures medium-late and averages between 1,300 and 2,300 kg/ha (between 1,160 and 2,050 lb/acre), a yield that is significantly higher than that of its Hallertauer parent. Crystal averages about 3% to 4% alpha acids, 2% to 3% beta acids, and about 21% cohumulone content. The essential oil profile of Crystal is nearly identical to that of Hallertauer Mittelfrueh, indicating excellent aroma potential. Like its Hallertauer parent, Crystal has no measurable farnesene in its essential oil fraction. Crystal is often used in place of German aroma hops in many specialty beers.