What is a hop?
For many, the extent of their knowledge of hops is from the ads they see on Sunday while watching the games. Miller lite boasts that their beer is “triple hopped.” To be honest… I really have no idea what that really is. Budweiser claims to use “seven types of hops” Whatever their practice is, hops are in beer and here to stay.
Hops are a perennial vine that is usually grown on trellis’. The flowers of the hops vine are picked after the develop and start to dry. They have a resinous texture to them and have an aroma that is something you have to smell. Generally pungent, grassy, citrusy, and/or earthy. The plants prefer to grow in upper latitudes, 35-45 degrees north in the northern hemisphere and the same south in the southern. Each spring the vine will pop out of the ground and can grow up to two feet per week. At the end of the growing season, each fall, the vine dies back to the ground to over winter and then the process is repeated.
Hops are available to brewers in three somewhat traditional forms and more recently a fourth form is available. Hop extract, which I will not go into today. The most common type used for homebrewers and many commercial brewers as well is the pellet hop. The hop cones are shredded and compressed into little pellets that are sold by the ounce or by the pound. Your average 5 gallon batch of homebrew will have between half and ounce and up to a full pound for some of the more extreme IPAs (India Pale Ale). Next week have whole hops, which are exactly as they sound, the whole cone is dried and used in the beer. The third and less common type is plug hops. Plug hops are the compressed whole hops into a plug, generally used for late additions to the boiling beer or wort or used as a dry hop addition, added after the boil is done and the beer is aging.
The varieties of hop are many. Just about every continent, except for Antarctica has them. Europe has a few varieties that are called “Noble hops”. These hops are traditionally used in German, Belgian, and Bavarian styles of beer, where the characteristics the brewer is looking for is an earth, piney, non-citrusy flavor and aroma. By comparison, many of the varieties that have been developed and are being grown in the US are very citrusy or smell/taste of tropical fruit, such as pineapple, papaya or mango. Others have flavors of apricot or blueberry.
Hops are generally added at three main points during the process. The first addition is the “bittering” addition. The boiling of hops in beer isomerizes the alpha acids in them, or makes the bitterness soluble in water… the bitterness stays in the beer. The next addition is normally in the last 20 minutes of the boil, this is called the “aroma” addition. This is the “in-between” addition. The alpha acid in the hops isn’t fully isomerized and the flavor somewhat driven off. The final addition is normally in the last 5 minutes of the boil up to and including after the heat has been turned off…. the “flavor” addition.
There is one additional addition that I purposefully left out… they “dry hop”. Dry hoping is the addition of the hops after the initial fermentation. The character that the beer receives is different from the previous mentioned additions. Some people believe that dry hoping is a waste of material. Others will not brew a beer that does not have at least a little dry hopping. Personally, I think it is a style option. Before I mentioned IPA. Dry hopping was started in the colonial days when England was shipping beer to it’s soldiers in India. The beer was not faring well on the long trip around Africa on it’s way to India. So brewers started adding hops to the casks to help preserve the beer. It worked! Hops have a preservative characteristic to them.
So… there you have it, the basics on hops.