Hops add bitterness, flavor and aroma to your beer while acting as a natural preservative. They come in a wide variety of types that originate from regions all over the world. Some are used predominantly for bittering while others are prized for the flavors and aromas that they impart. Regardless of which type is used to make a particular beer, it wouldn’t be beer without the hops.
All styles of beer contain hops, however the type of hop and the amount used is a big part of what makes that beer. Additionally, the way in which the hops are used in the process of making the beer can vary widely and play an equally important role as the type and amount used.
The Chemistry of Hops
The hop plant contains three main components: alpha acids, beta acids and essential oils.
Alpha acids are important to the bittering capabilities that hops can have while beta acids and essential oils are integral in adding flavor to a beer. The essential oils can also play a big part in contributing to the aroma.
Using Hops High in Alpha Acids
Hop varieties differ in the amount of each component that they contain which lends each to be used for different purposes. Hops that are high in alpha acids are ideal for bittering and added during the beginning of the boil.
This is because alpha acids go through a chemical reaction known as isomerization, in which the acids are transferred from the hop to the wort through a process that can be thought of as similar to absorption. The acids would typically act like an oil and repel the wort, but in the heat of a boil the acids are altered and can attach to the water molecules in the wort.
Some popular high alpha acid hops include Chinook, Columbus and Simcoe.
Using Hops Low in Alpha Acids
Hops that are lower in alpha acid content but have a greater presence of beta acids and/or essential oils may not necessarily be ideal for adding bitterness to wort but can be very effective in adding flavor to a beer.
These are typically added later in the boil for flavoring or at the end of the boil for adding aroma. Adding them later in the boil allows you to preserve the natural characteristics of the hop since they are not subjected to high levels of heat for an extended period of time. Furthermore, there is another method for using hops in which they are not added to the boil at all—this is known as dry hopping.
Some popular varieties that fall into this category are Cascade, Fuggle and Kent Golding.
What is Dry Hopping?
Dry hopping is the process of adding hops directly to a beer post-fermentation. While some add them post-boil and pre-fermentation it is not recommended, as the active nature of fermentation would eliminate any effects the hops could have on the beer. Instead, it is recommended that one dry hop during secondary fermentation, or the clarification stage, in which the active fermentation stage has already reached completion. As with any other usage of hops, when dry hopping you can use hops in whole leaf or pellet form, but it is recommended that they be higher in essential oil content.
To dry hop your beer, simply pour them directly into the secondary fermentation vessel. Hops are anti-microbial in nature so adding them without sterilizing them first is completely acceptable.
Additionally, you are adding the hops into a post-fermentation environment where the alcohol levels are too high to play host to any bacteria that could be introduced with the hops. Allow the hops to remain within the secondary fermenter for 10-14 days. You will notice that the hops may break down during the dry hopping process so allowing the proper amount of time lets the particles sink to the bottom of the vessel to ultimately create a clearer beer.
Additionally, you can contain the hops while dry hopping by using a nylon mesh bag like those used for boiling grain. You can also use a muslin bag, which is made out of cloth and has a coarser pattern than the fine mesh of a nylon grain bag. Either one of these options will certainly reduce the amount of hop particles in your beer but may also reduce the amount of exposure the beer has to the hops. Consider trying each method in addition to no bag at all to see which you prefer.
When dry hopping, it is recommended that you start out by using 1 oz. of hops per 5 gallons of beer. As you continue to experiment you can certainly increase the amount of hops, but an ounce is a good starting point. Keep in mind that a particular hop does not have to be restricted to one certain purpose or usage. Hops with a higher alpha acid content can certainly be used for dry hopping or flavoring but it’s simply a matter of finding the right balance. While dry hopping has historically been reserved for lagers, IPAs and pale ales, it is becoming increasingly more common to dry hop other styles as brewers try to discover new frontiers in beer.
All in all, hops are a very versatile ingredient that has endless possibilities.