Hop of the Week: Hop Breakdown

Hops are one of the main ingredients in beer, and according to the Reinheitsgebot (Bavarian Purity Law) it is one of four ingredients allowable when producing beer. 

But what are hops? I am going to attempt to give a breakdown of that little green bud that does so much for our drink of choice.

History: Before the introduction of hops to beer, ancient brewers used all kinds of different herbs to balance out the sweetness of the malt in beer. Some of these herbs would include types of evergreen like juniper and heather, or other bitter herbs like dandelion, licorice, anise, mandrake, and horehound. Hops began being bred in Europe during the 8th century. During this time they were used for different types of medicines because of the antiseptic quality they were believed to possess. It is debatable, so I will just say that hops were first used in the process of beer production somewhere between the 10th and 11th centuries. After the first introduction of hops it was noticed that they had a somewhat antibiotic effect and contributed to a better stability of beer, warding off any organisms that were undesirable in the finished product. Since then hops have been used in beer for flavor, aroma, and stability.

Production: Hops are produced all over the world and thrive best around the 48° latitude. They are however produced in many different areas of the globe each growing climate being a factor in yield and oil compositions which have an effect on flavor and aroma. Hops are a bine plant, which use different means of climbing then vine plants. Hops use their big stem and hairs to aid themselves in climbing upward. Hop fields are planted with high overhead stands that have a wire that allows each hop plant to grow tall.

*found at http://www.forestryimages.org

After harvest, hops are for the most part dried (some craft breweries use fresh hops for certain beers) and stored as three different types:

Whole: Nothing is done to the hops after drying. These are the quickest to degrade.

 Pellet: Hop material is ground and highly compressed into pellet form. These will last the longest but are harder to separate from the wort. 

 

 Plug: Hop material is also compressed but into a larger form, mostly 1 oz plugs, which make it easy for the homebrewer for measurement. After re-hydrating in the wort they will return mostly to their original form.

Results from all three are basically the same. Craft breweries will usually use the first two examples. 

Composition: Hops have two main resins, alpha acids and beta acids, that contribute to the end product in beer. Alpha acids impart the bitter flavor in beer that balance out the sweetness of the malt. To achieve this the alpha acids must isomerize during the boil, which is why the bittering addition is usually added at or near the beginning of the boiling process. Beta acids do not contribute much to the flavor of a beer, they do not isomerize in the boil and have a bigger factor in the ending aroma of a beer. Hops with high amounts of beta acids are usually saved for end additions so the compounds are not completely boiled off. However some beta acids can oxidize into non desirable compounds in beer.

Along with the acids hops have essential oils that contribute to the aroma and flavor that is produced in the ending product. The hop varieties that have desirable flavor and aroma traits are usually reserved for later boil additions so that the essential hop oils are not evaporated out. Flavor additions are usually not boiled more than 30 minutes, mostly added between 10 and 20 minutes left in the boil. Aroma additions are usually added very close if not at the end of the boil. Dry hopping is also a technique used in today's craft breweries. This is the act of adding hops after fermentation has completed. This allows the hop oils to penetrate the beer without being able to evaporate with a violent boil or fermentation. Dry hopping has a great affect on the aroma of a beer. The four main essential oils are Myrcene, Humulene, Caryophyllene, and Farnesene.

All of these compounds are produced in the lupulin glands,if holding onto a whole hop you will notice a yellow sticky substance referred to as lupulin.

Key facts: If you are a dog owner be sure to keep your dogs away from hops. They are highly toxic and will kill a dog in small amounts. Hops are a homeopathic medicine used for sleeplessness, restlessness, and insomnia. Hops degrade quickly when in the presence of light and air, store in a dark cool place preferably under a vacuum.