Module 03: Hops
Module three was all about hops – everything you ever wanted to know and more.
This session went super in depth into the different products and flavors of hops as well as how to evaluate and utilize. But let’s focus on the essentials in this breakdown:
What are hops and how are they used?
Hops are the female flowers from the Humulus lupulus plant. They are used in beer to help preserve it against microbial infection by bacteria as well as to add flavor. There are many varieties of hops, each with their own flavor and aroma profile (which we will touch on a little later). The lupulin glands within the hop contain the essential oils and resins of the hops flower. The resins provide the bitterness in the beer and the essential oils provide much of the aroma and flavors associated with the hops used. Hops help give depth and earthy-balance to the other ingredients, malted grain, water, and yeast.
Where do hops come from?
There is evidence of hops being used as early as 822 A.D. Nowadays, you can find most of the hop growth in the United States in states that border Canada. Up north is the best place to meet the specific conditions needed for hops growth. Temperatures need to stay between 30 to 52 degrees and get 15 hours of daylight. They need a growing season of around 120 days, followed by a cool dormant time of between six to eight weeks (which is when it begins to grow hops). Once harvested, at maturity, hops are dried and then further processed into pellets, extract, or remain as cones.
How do you select hops for beer?
Hops are carefully selected and evaluated on both a physical level and internal (resin/oil) level to ensure the hops are what you want to use for your beer. Hops are susceptible to diseases due to things like mildew, wilt, or insects. So as part of this physical evaluation, you are looking for any potential damage to the hop, moisture, and stability of the cone itself. The way to evaluate aroma is very interesting: you take a whole cone and rub it in your hands lightly to release the internal oils and let you smell the aroma.
Overall, being able to reproduce a beer (with the same taste and aroma) is extremely important and stems from your hop selection. Your hops evaluation team should be trained and able to pick the hops that are needed to make your beer consistently. While you may come across the “perfect hops,” you don’t always want to pick it because you may not be able to reproduce it season after season. Consistency and reproducibility are key.
What are some common aromas of hops?
Much of the flavor and aroma of a beer, that come from hops, are attributable to compounds in the oils, such as:
- Myrcene: green, resinous and herbaceous aroma (often found in thyme)
- Humulene: woody or piney (found in pine, sage)
- Caryophyllene: woody (found in caraway, black pepper)
- Farnesene: floral, mildly herbaceous aroma (found in fruits, herbs, spices)
- Citronellol: citrusy, lemon aroma (often found in lemongrass, geraniums)
- Geraniol: sweet, floral aroma (found in geraniums)
- Linalool: sweet floral, citrusy aroma with light spice notes (found in coriander seeds, lavender, basil)
- 3MH, 3MHA, and 4MMP: blackcurrant and grapefruit aroma
- Esters: fruity aromas and taste, like apple, pineapple, and apricot
How do you add hops to beer?
The best utilization of hops depends on the variety of hop and the style of beer being made. The amount of hops and timing are very important factors to consider, along with kettle efficiency, the form of the hops (whole cone vs. pellets vs. extract), the gravity of the wort, the boil temperature, the pH, and the composition of the hops. We won’t get into all of that, but here are some of the most common ways of adding hop:
In this process, you add hops directly into the mash (along with your grains). This technique can improve the overall flavor of the beer and provide more depth of flavor, without adding much bitterness. Since the hops are not exposed to boiling temperatures at this stage the bitter components are not released.
Most hops are typically added during the boil. The length of the boil is typically no shorter than 60 minutes and some go as long as 120 minutes or even longer. Hops are added at different points throughout the boil to release different flavors. Hops added to the beginning of the boil are for bitterness. Boiling releases alpha acids that provide bitterness in your beer, so the longer you boil your hops, the more bitterness you add. Late additions of hops, within the last 15 minutes, focus more on adding aroma. These are added at the end because if they are boiled for too long the aromatic flavors disappear.
Dry-hopping is done post fermentation and provides a great deal of aroma to beers that undergo this treatment. During the boil, many of the more volatile compounds are lost, so dry-hopping can put those compounds back into the beer without adding bitterness. This process can be done while still at fermentation temperature or colder. The hops are added and can be left for days or weeks.
So there is your crash course on hops! Next, we’ll take a look at the brewhouse and the setup needed to make this whole process possible. If you missed my last post about malt and the science of mashing – check it out!