• Biodiversity Hops
  • Facts About The Spice of Beer - Hops

    Humulus lupulus

    First, our short video

    Here are a few facts about Hops

    • Hops grow vertically on bines, not vines. The difference in the two is a bine grows upward climbing around a separate support, whereas vines grow on a structure using tendrils and roots.
    • One IBU (International Bittering Unit) is defined as one part-per-million (ppm) of the chemical isohumulone, the alpha acid in hops that contributes to its bitter flavor
    • Essential hops oils are easily lost to oxidation. One USDA study found losses of 28% to 90% after six months of storage at room temperature, depending on the hop varietal.
    • Only female hops have the gland that produces oils desirable for brewing. Male and female hops grow on separate plants, so male hops are removed to prevent fertilization. Large commercial hops fields are entirely female.
    • On a related note, hops are one of the plant species (along with soybeans, legumes, flax seed and many others) that contain phytoestrogens, plant-derived nonsteroidal compounds that mimic the human sex hormone, estrogen. The health effects of consumption of phytoestrogens by either men or women is largely inconclusive at this point.
    • Hops contain complex organic compounds such as xanthohumol, which is currently under research as a potential cancer chemopreventative and treatment for postmenopausal symptoms.
    • The alpha acids in hops have a mild antibacterial effect against Gram-positive bacteria such as Lactobacillus and Pediococcus, giving a slight advantage to the Gram-negative spores of brewer’s yeast, Saccharomyces. This property is one of the reasons why hops won out over many other herbal bittering agents when brewers noticed less spoilage in batches brewed with hops.
    • As widely reported in craft beer literature — for no apparent reason — hops belong to the same taxonomic family (Cannabaceae) as cannabis, hemp and sativa, along with 170 other plant species. Other than possessing mild antiseptic properties, there is little similarity among any of these plants other than their shared academic classification.
    • Hop resins are insoluble in water. It takes the application of heat during brewing to isomerize (change the chemical structure of) alpha acids so their flavors can dissolve into the wort.
    • Hops are toxic to dogs and cats, sometimes even in small amounts depending on the breed. Keep an eye on your hops pellets if home-brewing.

    Related Topics

    Written by Rob Nelson

    Rob is an ecologist from the University of Hawaii. He is also an award-winning filmmaker. As principle director of Untamed Science productions his goal is to create videos and content that are both entertaining and educational. When he's not making science content, he races slalom kayaks and skydives.

    You can follow Rob Nelson