Hops are the green, cone-shaped flowers (also called seed cones or strobiles) of the hop plant, scientifically known as Humulus lupulus , a climbing perennial plant in the hemp family (Cannabaceae)

. Only the female plants produce these cones, which are used primarily in brewing beer. Hops serve several key functions in beer production:

• They provide bitterness that balances the sweetness of malt.
• They contribute distinctive floral, fruity, citrus, piney, or grassy aromas and flavors.
• They act as a natural preservative due to their antibacterial properties, helping beer stay fresh longer.
• They help beer retain its foam head, which is important for aroma and flavor perception

Inside each hop cone are tiny yellow glands called lupulin, which contain alpha acids responsible for bitterness, as well as essential oils that give hops their characteristic aroma and flavor

. Hops are grown commercially in temperate regions with moderate climates, rich soil, and good sunlight, such as the Pacific Northwest of the U.S., Germany, Czech Republic, and New Zealand

. In summary, hops are a fundamental ingredient in beer, valued for their flavor, aroma, bitterness, and preservative qualities, making them essential to the brewing process.