Today I am going to cover hops. Hops were once considered a weed, and were coined as a wicked and pernicious plant. Today, however, they are an integral ingredient in beer. I will cover what is in hops that we want, and why we use hops. I will tell you how to use hops in the brewing process. We will go over when to add them and which hops are best to use in certain situations. I'll finish by explaining how best to store your hops.
What are hops anyway? The hops we use in our beer are actually flowers, from the plant Humulus lupulus. Hops have been used in beer since just after 800 AD. Before this time, a variety of herbs were used instead, making a type of brew called a Gruit. The part of the hop that we are most concerned with is the sticky yellow lupulin glands. These contain a stunning array of chemicals. The bitterness from hops originates from alpha-acids found in these glands, and all of the aromatic oils and resins are located here as well. Hops are sold most commonly in either whole cone or pellet forms. Hop varieties are described as bittering, aroma, or dual purpose.
Why exactly do we use hops in our beer then? The most important reason to use hops is to balance the sweetness from malt against the bitterness from the alpha-acids. We also depend on hops to provide our beer with unique characteristics. These aromas and flavors cannot be re-created with other ingredients. Hops help to define styles from around the world. Regions around the world produce unique hops that define the beers made there.
Lets move on now, and discuss how we add hops to our beer. There are conventionally four different times that we add hops to our beer. The first is called our bittering addition, which is at the beginning of the boil. The second addition you can make is 10 to 15 minutes before your boil is over, and is called the flavor addition. Soon after this, you can add your aroma addition. This addition is best done with just 5 minutes left in your boil. The final addition I will mention is dry-hopping. This is an addition of hops to your beer in the fermenter, preferably after fermentation is done. You should always add any hops in a hop sock or a nylon straining bag. This keeps the hops out of your finished beer.
Your bittering addition as I said is added at the beginning of your boil. This addition is the main source of bitterness in your final beer. The bitterness comes from a chemical reaction in which alpha-acids turn into isomerized alpha-acids. Longer boils, more hops, or hops with more alpha-acids make beers with more of the bitter isomerized alpha-acids. The aromatic oils and resins are easily evaporated during the boil, so almost none of these remain in the finished beer.
Flavor hops are the next addition to your beer. Since this addition is later in the boil, a very small amount of alpha-acids are turned into the bitter isomerized alpha-acids. Much more of the aromatic and flavor compounds are left behind. There is a balancing act going on here. The later you add hops, the more aromas will be in the beer. The sooner you add them, the more flavors will be present. But, if you add the hops too early, all the flavor and aroma will be boiled-off. The flavors you can expect to find include citrus, pine, fruit, woody, earthy, flowery, and perfume, all depending on the variety of hop you use.
Now lets move on to the aroma addition. This addition of hops is done as late in the boil as possible in order to preserve as much of the volatile aromatic compounds in the hops. There is almost no bitterness contributed from this addition. By adding these late addition hops, you add unique aromas to your beers, and there is a large variety of hops bred for this purpose. These aroma hops are rich in oils and resins, and are most often low in the bittering alpha-acids.
The final addition I will describe to you is called dry-hopping. This is a method of adding intense hop aroma and flavor to your beer. The technique is simple. Just add the hops to your fermenter once fermentation is over. Use a hop sock or nylon bag just like in your boil, just be sure to sanitize the bag you use. Because there is less heat involved here, the process takes longer. I recommend letting your beer sit on the dry hops for 4-5 days. This is a very common practice in America, but is much less common world wide.
As I said earlier, hop varieties are usually split into either bittering or aroma hops. Bittering hops have much more bittering potential from the copious amounts of alpha-acids in the cones. More alpha-acids equals more bitterness in your beer. Aroma or flavor hops have more soft resins and oils that produce the myriad characteristics found in beers. Some hops contain balanced amounts of each chemical, and can be used for either purpose. When trying to re-create a beer from a region in the world, start with hops from that same area.
So lets take a moment to review some hop varieties, their general flavors, and where they originated from. Hops grown in America tend to be much higher in alpha-acids and aromatic compounds. Some common American varieties include Cascade, Centennial, Amarillo, Sterling, Columbus, Chinook, Simcoe, Citra, Williamette, just to name a few. The amount of varieties is staggering. Typical flavors and aromas in these hops are usually very citrusy and piney, and can include hints of mint, onion, fruit, and earthy notes. These hops are great for American style beers such as Pale Ales, IPA's and Amber Ales.
Moving over seas, the next variety of hops come from Europe. Most of these varieties are termed Noble hops, because they were the first to be cultivated. These hops are usually lower in alpha-acids as well as the aromatic oils and resins. Common noble varieties include Hallertauer, Tettnang, Saaz, Tradition, and Northern Brewer. There are some American Noble varieties that are grown domestically, including Liberty, Mt. Hood, and Galena. These all have notes of perfume, flowers, earthy and woody tones, and are all considered good hops for the traditional European ales and lagers.
Finally, we come to the English hops. These hops are usually lower in both alpha-acids and aromatics than American varieties, but are much more balanced. Some English varieties include Fuggles, Kent Goldings, Nugget, Target, or Admiral. There are American bred English varieties that have the same characteristics as their English cousins. You can expect unique floral notes and strong woody, herbal aromas from these hops. Mint, fruits, grassy, and mild pine notes are common as well. If you want to emulate the classic ales of England, these hops should be your first choice.
LetÃ¢ÂÂs switch gears here and talk for a moment about storing your hops. Hops are a very perishable product. You should use hops as soon as possible. Any unused hops are best stored in an air tight container in your refrigerator. The aromatic oils and resins are not stable, and are especially reactive with oxygen. When this happens, you get cheesy and sweat sock flavors and aromas. These flavors have no place in your beer. To avoid this we ship our hops in bags that block oxygen. You can use zip-lock bags at home.
Hops are a crucial ingredient to modern beers. They are used to balance sweetness from the malt and add flavor and aroma. Hops are added directly to the boiling wort at various times, or added to the fermented beer to steep. Hops are perishable, and must be stored properly. Choosing your hop variety is a fun and exciting way to create unique beers, or re-create classic styles.