Learning Lab: Hops Aroma and Flavor

Learn how to work with mini- batches to supercharge your progress toward becoming a better brewer. This column examines how you can use 1 gallon (3.8 liter) mini-batches to explore hops aroma and flavor.

Jester Goldman Jan 5, 2019 - 12 min read

Learning Lab: Hops Aroma and Flavor  Primary Image

One of the best parts of homebrewing is the desire to push further, to always improve, and to understand not only how ingredients come together and work together but the science that ties it all together. Every batch you brew builds your confidence and extends your knowledge, especially as you branch out to explore your own recipes or fine-tune an earlier one. Unfortunately, with each batch taking at least three or four weeks, the learning process can seem awfully slow.

In my career as a homebrewer, I’ve found that the best way to gain that experience more quickly is with a scaled-down experiment. It starts with a mini-batch of a baseline-beer recipe that provides a simple canvas for variations on a theme. The key is to resist the urge to tackle everything at once. Instead, focus on one aspect of brewing at a time to maximize your learning. A great place to start is getting to know your ingredients better because they provide the foundation of your beer. There’s plenty to learn about malt and yeast, but this issue, let’s look at how we can explore hops aroma and flavor by focusing each of our mini-batches on a single target hops variety.

To maximize both aroma and flavor, each 1 gallon (3.8 l) mini-batch will get a dose of the selected hops at flameout, followed by dry hopping once primary fermentation settles out. Over the course of a day or two, it’s easy to start four or five of these small batches. When they’re done, you’ll have a perfect tasting kit to showcase the hops varieties you’ve chosen.

Since most homebrewers also appreciate craft beer, you probably already have some familiarity and might recognize a few hops varieties. Maybe you already associate Saaz hops with “spicy” or Cascade with grapefruit. Descriptors such as citrus, piney, or earthy are useful, but real-life sensory experience will teach you so much more about the differences that each one can bring to your beer, especially if you don’t have to dedicate all your brew time to making simple batches for learning.


Before You Start

Unless you’re already familiar with brewing at this smaller volume (1 gallon/3.8 liter), you’ll need to figure out your evaporation. Evaporation during the boil affects the sugar concentration, which impacts starting gravity and hops utilization.

Uniformity across the mini-batches is important because we want to focus our sensory evaluation on the hops aroma and flavor, not variations in the base beer.

Evaporation is often tracked as a percentage of boil volume per hour, but it’s more dependent on how vigorous the boil is and the geometry of your brew pot, regardless of the boil volume. It’s best to take a little time to figure this out beforehand by boiling a gallon of plain water for an hour and seeing what the loss is. When you brew your mini-batch, add that lost volume to 1 gallon (3.8 l), which should leave you with a gallon at the end of your boil. For my 3-gallon (11.5 l) pot, that worked out to just over 2 quarts (1.9 l) extra. So, I began my boil with 6 quarts (5.7 l) total liquid.

Choose Your Target Hops

There are several directions you can go with choosing the hops to test. If you’re just getting started as a brewer, one of the more useful ideas is to shotgun sample the wide world of hops. In this case, you would dedicate a mini-batch to each of the major hops families, picking a representative variety from the noble hops (e.g., Hallertau, Spalt, or Saaz), British hops (e.g., Fuggles, Kent Goldings, Northern Brewer), American C-hops (e.g., Cascade, Centennial, Columbus), and fruity New Zealand varieties (e.g., Nelson Sauvin, Galaxy). This is a good intro because each of your sample beers will starkly contrast with the others.


Alternatively, you could pull a survey of your local homebrew shop’s hops stock, especially with some of the unfamiliar strains. Ekuanot? Calypso? Rather than risk a full batch figuring out how they work, let a mini-batch show you what they’ve got to offer.

Mini-Batch Process

You might be tempted to brew a full 5-gallon (19 l) batch of the baseline wort and split it up for the hops stand. Resist that urge! Even if you have five 1-gallon (3.8 l) pots to use for the hops stand, it would be very unwieldy, and the last batches to chill would end up with a much longer hops stand. Instead, I recommend handling each mini-batch on its own. You won’t save the time of overlapping the 60-minute boil, but it’s much easier to give each batch the same hops-stand experience for consistency. It’s also a good idea to use malt extract for this experiment, even if you’re an all-grain brewer. You’ll save the time and eliminate any mash-related variables.

Baseline Batch
Volume (after boil): 1 gallon (3.8 l)
OG: ~ 1.053
IBUs: ~ 40

1.25 lb (567 g) Light dry malt extract (DME)
0.125 oz (3.5 g) Centennial hops [10% AA] at 60 minutes (You can substitute any relatively neutral bittering hops—just aim for around 40 IBUs.)
1/2 package Safale US-05 American Ale yeast


Dissolve the DME into the initial volume of water (1 gallon/3.8 l) plus the makeup for the evaporation loss—see “Before You Start,” page 22), then bring to a boil. Add the bittering hops and boil the baseline wort for 60 minutes.

Add 0.75 oz (21 g) of one of your target hops at flameout. Whirlpool and cover. Let sit for a 20-minute hops stand. Chill the wort down to pitching temperature (use a cold-water bath or immersion chiller). Transfer the wort to a gallon (3.8 l) jug and pitch the yeast.

Once primary fermentation is complete, dry hop with another 0.25 oz (7 g) of the same target hops.

After 5 days, rack the beer off the hops and bottle it with about 0.8 oz (23 g) totally dissolved priming sugar.


Repeat for each target hops variety you’ve selected.

Pre-Taste Study Work

While you give the beers a couple of weeks to carbonate, you should put together some study materials. Go online and collect a set of aroma and flavor descriptors for each variety of hops you brewed with (hops vendors’ and homebrewer websites can be great sources).

As an example, my online search on Ekuanot hops yielded a list including tropical fruits such as papaya and melon, numerous citrus references such as lime and orange peel, and then a wild mix of other aromas such as green pepper, apple, berry, cedar, sage, bay leaves, eucalyptus, clove, pine, and tobacco. Your list of descriptors will be a cue sheet for the tasting session.

Time to Sample

Assemble what you need for your tasting session: cue sheets, clean glassware (tulip glasses are recommended for preserving the aromatics), and some paper to use as a tasting log. Divide each tasting sheet into separate sections for aroma and flavor. Pick one of the beers and review its cue sheet for a list of aromas and flavors to look for. Open the bottle and pour about a half glass.


Take a quick sniff, followed by a deeper inhale. Refer to your cue sheet and note all of the descriptors that you perceive in the aroma section of your tasting log. Take another sniff with your mouth open and see whether that gives you any more details. Are there other aromas that aren’t on your list? Write those down as well. It’s also good to capture less direct associations such as “cut flowers at my grandmother’s house” or “digging in the forest.” These will help anchor your sense of the hops character.

After a first pass on aroma, you’re ready to check out the flavor. Take a small sip and swallow quickly, then go back through your list. Are you getting anything new? Mark it down in the flavor section. Try another sip, but swish this one in your mouth for a moment. Another good technique is to swallow, then exhale through your mouth.

Once you’ve tracked all of the descriptors that seem to fit, whether from your cue sheet or associations you find on your own, it’s time to move on to the next beer in the set. Before you do, cleanse your palate with a saltine cracker or some bread. You can reset your nose by lightly sniffing some coffee beans or by holding your nose to your inner elbow and inhaling a breath or two.

After you’ve evaluated the second beer, go back to the first one. How is it similar to the one you just finished? How does it differ? If you find something new, make a note on your tasting sheets before resetting your palate and moving on to the next beer. As you try each of your samples, this review will help you understand the specific character of the hops.


By the time you’re done, you’ll have a thorough set of personalized descriptors for each hops variety. Consider running a follow-up session later to run through the beers again. If you do, change up the order to see whether it helps you find more details.

Graduate Studies

The best part of this approach is that it’s fairly easy to run through again, changing out the hops to extend your knowledge or refresh your sense of a variety in a different context. A good follow-up would be to compare hops within the same family.

Take the C-hops, for instance: Cascade and Centennial are fairly similar, with the same descriptors, so learning the nuances is particularly useful. Round out the experimental set with Columbus and Chinook to explore more of the piney side. You could also include Citra to get a different version of citrus character from Cascade’s grapefruit/citrus peel.

Once you work your way through the main hops families, your advanced training could focus on exploring hops that are often suggested as substitutes for one another. Aside from the Cascade-Centennial face-off I mentioned above, you could explore Fuggles vs. Willamette, Hallertau Mittelfruh vs. Liberty, or Cluster vs. Galena.

This is great practice for judging beer, but more importantly, you’ll be more confident finding exactly the right hops for your next recipe.