It’s part 3 of our 4 part blog series about the basic ingredients of beer. This month, we’re taking a closer look at hops.
What Are Hops? How Do They Impact Brewing?
The flower, or cone, on female Humulus lupulus plants are what we commonly refer to as hops. The cones are filled with perishable resins, and these resins are what give hops the characteristics that make them favorable for brewing beer.
In today’s beer, hops are used for their bitterness which makes them ideal for counter balancing the sweetness of introduced by malts. Hops can also be used to add flavors and aromas to beer as well as work as a preservative.
The resins in hops are naturally non-bitter and insoluble. When hops are added to the boil, these resins undergo a process known as isomerization which is a chemical change that transforms them to be both bitter and soluble. The longer hops are in the boil, the more isomerization that occurs, therefore leading to a more bitter final product.
History of Hops and Beer
While hops are now considered one of the four main ingredients in beer, people made beer for thousands of years completely without hops. A mixture of herbs and spices called gruit was traditionally used to flavor beer. Starting in the 16th Century, hops started to become more and more popular in beers throughout Western Europe and Great Britain.
One of the original appeals of adding hops to beer is that it worked as a preservative. You may already know that India Pale Ales got their name because they were often brought along the months long journey from Europe to India. These ales were stored in barrels with hops to make sure the beer wouldn’t spoil throughout the course of voyages.
It wasn’t really until American microbrewers fell in love with hops that hops started taking a primary role in the beer brewing process rather than a supporting one.
Different Uses for Hops
The amount of bitterness, flavor, and aroma that hops add to beer is highly dependant on how a brewer uses them. In addition to adding hops at various stages of the boil, they can also be added near the end of fermentation.
To get the best bittering effects from hops, they should be immersed in the boil for about an hour (45 minutes minimum, 90 minutes max). As mentioned above, the longer the resins in hops are exposed to heat, the more isomerization occurs leading to more bitterness being extracted from them.
Hops added for the final 20-40 minutes of the boil are typically for flavoring purposes. This amount of time allows isomerization to occur but keeps the beer from becoming as bitter. Flavoring hops are useful for adding some bitterness in addition to hop flavors to beer.
When hops are added to the boil for 15 minutes or less, they are known as finishing or aromatic hops. This short period of time in the boil effectively limits the amount of bitterness and flavors that are passed on while aromatic oils that tend to boil out during longer immersion times remain to leave a hoppy aroma.
Dry hopping is the technique of adding hops to the fermentation vessel after fermentation has completed. Because there is no heat source, isomerization doesn’t occur, and the hops don’t add bitterness or any lasting flavor. However, dry hopping is a useful tool for adding a strong aroma to beer.
Different Forms of Hops
Hop pellets are highly processed hops consisting of finely powdered hop cones compressed into small tablet forms. Even though they look commercialized, you can use them for homebrewing applications. One thing hop pellets have going for them is they are 20%-30% stronger by weight than the same type of hop in loose form. These concentrated little pellets are first processed to remove the non-resinous materials in the hops, thus reducing the weight and volume of the hops. Most hop pellets are made from a blend of hops to maintain consistent alpha acid levels.
Hop plugs are whole flowers that have been dried and compressed into a plug. Many people say that the hop plugs produce a better aroma and flavor than the hop pellets. Because hop plugs have a small surface area, their exposure to the wort is minimized and is less efficient for bittering. You’ll need to use more plugs to match the amount of bitterness imparted by hop pellets.
Whole leaf hops are exactly what they sound like, whole hop flowers dried and uncompressed. This is the original way beer was brewed for centuries, but that doesn’t mean it’s the best way anymore. Whole leaf hops are no more “fresh” than pellet or plug hops. They require more space to store, and they don’t settle out in the kettle and fermenter as nicely as hop pellets do. Due to their loose leaf structure, they are more susceptible to oxidation and degradation than plugs and pellets. Finally, whole leaf hops run into the same problem as hop plugs, they don’t impart as much bitterness to your brew as hop pellets.
A lot of people have varying feelings when it comes to using hop extracts to fortify your homebrew. My personal opinion is that it’s no different than using chili spices when cooking a dish instead of dicing up fresh chili peppers. Sometimes fresh peppers are called for because you want that added texture and moisture, but other times you’re happy with your meal’s consistency and just want to heat it up a notch. Same goes with hop extracts. It comes down to the brewer and his or her use of those extracts. If you’ve ever had a pint of Pliny the Younger, then you’ve had a fine brew that uses hop extracts in conjunction with pellets. Honestly if a bitter beer is what you’re brewing, using hop extracts can be very beneficial because you won't soak up too much of your wort using tons of hops. Note: Use extracts sparingly at first until you have a handle on the impact to flavor that a small amount can have on your homebrew.