Beer Industry Resources
16.1.09
What Are Hops?
In a recent post we discussed how high hop prices were impacting the U.S. craft brewing industry. So what exactly is a "hop" after all, and what is its function in the brewing process? Well, let's take a closer look at this little green flower.
The hop is a climbing plant related to hemp, and there are both males and females. The females are the ones that are planted commercially because only the females produce the flower cones used in brewing. Once harvested, those flower cones are called hops, so the term "hop" can really refer to both the plant and the flower depending on the context. The importance of the hop flowers to the art of brewing comes from their utility as both a bittering agent and a contributor of aroma, as well as being a natural preservative adept at warding off bacterial spoilage.
The first documented evidence of hops being used in brewing comes from Germany in the 11th Century. Prior to it becoming a widespread beer flavoring and preservative, many other plants were used in beer, such as anise, juniper, spruce, pine, tree bark, wormwood, rosemary, and many others. Not until the 16th Century did hops become a component of British beer, and it was another century until hops began being grown in America.
Hops contain two types of acid useful to brewers known as alpha and beta acids, which both act as natural preserving agents by killing or hindering the growth of various bacteria. British brewers took advantage of this by brewing intensely-hopped beers (which eventually became known as India Pale Ale, or IPA) in order to prevent spoilage on their long journey to British colonies in India. The two acids are different in that typically alpha acids provide the bitterness in a beer while beta acids contribute to aroma. Therefore brewers select hop varieties that have high levels of alpha acid, like Columbus for instance, in order to add bitterness to the beer (which is important for balancing the sweetness of the malt); they select hops with higher proportions of beta acids, like Cascade, to add the specific aromas they desire.
Some brewers may only use a single variety of hops when brewing, for instance Saaz hops for a Czech Pilsner. Other brewers choose to use 2, 3, or even more varieties of hops to achieve layers of complexity, like the excellent Jamaica Brand Red Ale featured in April '08 from Mad River Brewing Company, which uses Cascade, Magnum, Summit, and Willamette all in the same brew, and to great effect we might add!
The hop is a climbing plant related to hemp, and there are both males and females. The females are the ones that are planted commercially because only the females produce the flower cones used in brewing. Once harvested, those flower cones are called hops, so the term "hop" can really refer to both the plant and the flower depending on the context. The importance of the hop flowers to the art of brewing comes from their utility as both a bittering agent and a contributor of aroma, as well as being a natural preservative adept at warding off bacterial spoilage.
The first documented evidence of hops being used in brewing comes from Germany in the 11th Century. Prior to it becoming a widespread beer flavoring and preservative, many other plants were used in beer, such as anise, juniper, spruce, pine, tree bark, wormwood, rosemary, and many others. Not until the 16th Century did hops become a component of British beer, and it was another century until hops began being grown in America.
Hops contain two types of acid useful to brewers known as alpha and beta acids, which both act as natural preserving agents by killing or hindering the growth of various bacteria. British brewers took advantage of this by brewing intensely-hopped beers (which eventually became known as India Pale Ale, or IPA) in order to prevent spoilage on their long journey to British colonies in India. The two acids are different in that typically alpha acids provide the bitterness in a beer while beta acids contribute to aroma. Therefore brewers select hop varieties that have high levels of alpha acid, like Columbus for instance, in order to add bitterness to the beer (which is important for balancing the sweetness of the malt); they select hops with higher proportions of beta acids, like Cascade, to add the specific aromas they desire.
Some brewers may only use a single variety of hops when brewing, for instance Saaz hops for a Czech Pilsner. Other brewers choose to use 2, 3, or even more varieties of hops to achieve layers of complexity, like the excellent Jamaica Brand Red Ale featured in April '08 from Mad River Brewing Company, which uses Cascade, Magnum, Summit, and Willamette all in the same brew, and to great effect we might add!
