The Many Forms of Hops

It’s a Bitter World

It’s hard to deny that hops have become the darling of the craft beer world over the last 20 years. While there are still plenty of malty beer enthusiasts, a trip to a local beer store and the respective shelf space taken up by hop-forward beers represents that its popularity is undeniable. It’s not surprising to many observers because the explosion of new hop varieties coming out of breeding programs has revolutionized the hop character that can be produced. If the term “tropical fruit character” were used 20 years ago to describe a beer, it probably would have implied a citrus element. Today, we think mango, pineapple, guava, papaya, and even coconut.

But it’s not just the new hop varieties that have pushed that hop mania we’ve experienced recently, it’s also been aided to some extent by a new look at yeast selection as well as the way in which hops can be delivered into the wort and beer. It is this last piece of that puzzle that we will be focusing on today. It’s good for every brewer to understand the different hop products available and ways to utilize them. Even if you are not brewing a hop-forward beer, an understanding of their pros and cons is beneficial.

Whole-Cone Hops

Many traditionalists enjoy what whole-cone hops can bring to a beer. Proponents cite an increase in the complexity whole cones provide because they are the least processed. After all, there is a reason many esteemed breweries like Sierra Nevada and Deschutes still utilize them in their lineup. Whole-cone hops do absorb a lot of liquid so are best utilized for low to moderately hoppy beers, or at key junctures in the process along with other hop formats in order to minimize beer loss. 

Breweries who still employ whole-cone hops in their recipes utilize various methods for hopping. As one example, Sierra Nevada adds whole-cone hops in the kettle and removes them with a continuous hop separator. For dry hopping with whole-cone hops, they have their Torpedo and still use giant bags for dry hopping Bigfoot. 

Homebrewers may have very specific uses for whole-cone hops. A hopback, where hot wort is passed through a canister packed with whole-cone hops, is the perfect example of when this format of hops is required. Mash hopping can also utilize whole-cone hops and they will provide the added benefit of creating space in the mash, similar to adding rice hulls. 

On the downside, whole-cone hops take up more space in cold storage and are also known to oxidize faster once the package is opened due to the lower density nature of the cones. Vacuum resealing of bags is by far the best way to store, flushed with CO₂ if possible.

Pellet Hops

There are several different types of pelletized hops, T-90 and lupulin-enriched pellets (sometimes referred to as T-45) being the most prevalent. Homebrewers are most familiar with the T-90 hops, although lupulin-enriched pellets are widely available these days and continue to gain traction. Basically, the number in format relays how much of the original hop cone material has been pelletized. T-90s represent 90% of the original hop cone with 10% of the vegetative material removed. T-45 has 55% of the vegetative material removed. This represents a more concentrated version of the remaining materials that brewers are mainly seeking from the lupulin glands of the hop cones: Alpha and beta acids and the essential oils.

One of the main benefits of hop pellets is efficiency; this means higher yields and less hops required to achieve the same hoppy results. Working with T-90 pellets not only offers the 10% saving of green material that will absorb liquid, but also when settled can form a more compact trub. This allows more liquid to get racked off the hops. Also, pellets have better storage life due to their dense nature.

For dry hopping, they are commonly cited as being superior since they typically submerse themselves, break apart, and fall to the bottom of the fermenter so you can easily rack your beer off of them. There is some exception to this, notably when low-density hop pellets end up floating and creating rafts on the surface of the fermenter. This is one reason why some breweries use special vessels for dry hopping with pellets via recirculation. To be safe, homebrewers can add pellets to a large and sanitized muslin bag with weights or place hops in a metal canister. If dry hopping in a Corny keg, the whole keg can be flipped twice a day (this is only advised if proper closed-racking techniques were employed). 

Also, pelletized hops release their oils much faster than whole-cone hops when dry hopping. Whole-cone hops can take 7–10 days to express the oils from the lupulin glands.  Pelletized hops do the same in 1–2 days.

A downside to them is they can clog up screens and specialty equipment is often required to remove pellet hop material. Also, while the pelletizing process has greatly improved over the years, there are some brewers who question the loss of oils and uniqueness during the procedure.

Lupulin-Enriched Hops

If you’re looking to brew a more hop-forward beer, this style of hop product has been designed with that recipe in mind. Big, bold hop flavors with less of the vegetative material found in whole-cone and T-90 hops, which can lend astringency and “green” character to a beer. While the processing is unique to each of these products, the end result is similar . . . increased lupulin concentration in each hop pellet. The biggest pro for these products is the minimized loss of beer when trying to achieve big hop flavor, like during dry hopping. While this may be great for that hazy or West Coast IPA you’re brewing, the lack of vegetative character may actually be a loss in a beer like a Pilsner.

Since many homebrew recipes are written for T-90 pellets, there will be a conversion that needs to happen unless a specific lupulin-enriched product is listed in the recipe. Going by the alpha acid content of the hop is one good way to scale proportionally. For example, you might find Centennial hop pellets at 22% alpha acids. If the recipe utilizes 11% alpha acid Centennial hops, then simply cut the amount used in half. A little calculator work may be required.

It’s also good to check with the manufacturer’s literature about their recommendations for dosage rates. For example when using Cryo Hops®, Yakima Chief Hops recommends cutting hop amounts in half compared to standard T-90 pellets for aromatic purposes. So if your recipe calls for 4 oz. (113 g) dry hops, you would want to use 2 oz. (56 g) of this product. Lupomax® states to use 70% of the recipe’s recommended rate — so in the above example that would be just about 3 oz. (85 g). There are other proprietary lupulin-enriched products out there like Lupulin™ from Hopsteiner and lupulin-enriched Type 45 from Germany’s HVG that actually can range from T-30 up to T-85.

Hop Extracts

To even further reduce hop material, we come upon the next two types of products: Hop extracts and distilled oils. While they have been around for about 40 years, hop extracts are a huge and growing field that is evolving as research into techniques to extract specific characteristics from the hop cone continues. There are several different classes of hop extracts now available from different manufacturers, often with a focus on a specific purpose or usage in the brewery. Brewers can now brew a big IPA without utilizing a single hop cone or pellet.

Disposable pipettes and syringes are a common delivery mechanism for these products on a homebrew scale. Quite a few have very small to minute dosage rates, so some research into this should be done prior to purchasing. Others have been designed specifically for homebrew-scale and don’t require any outside equipment for measuring dosing rates. Warming the products up some prior to dosing may be helpful in some but not all cases.

Iso-Extracts

We’ll start off with the concept of simply adding bitterness to a beer. To be clear, there is no aroma enhancement with iso-extracts. These products offer pre-isomerized alpha acids that can be added either to the kettle, whirlpool, or fermenter to achieve bitterness in a beer. There are several different types and concentrations of iso-extracts. Variations include rho, tetra, and hexa, each with its own set of enhancement characteristics. 

Some, most notably tetra, have the added benefit of a positive effect on foam retention of beer as well as body enhancement. Some will provide microbial protection while others can help prevent light strike from occurring. So if your beer is going to be poured at a daytime brewfest, that could be a great opportunity to try a light-stabilized iso extract for bittering. Also, high-altitude brewers may find iso-extracts an efficient way to achieve enhanced bitterness when such a profile is desired.

CO₂ Extracts

CO₂ hop extracts (sometimes referred to as hop shots) are great for adding bitterness and hop character during brew day and are typically sold in syringes for homebrewers. Like the iso-extracts, these get IBUs into a beer without adding any vegetative material. Suppliers will often state how many IBUs one milliliter of a CO₂ hop extract will add to a 5-gallon (19-L) batch of beer. Always add CO₂ extract off heat and stir until fully dissolved before turning heat back on.

CO₂ extracts for a long time were generally not very user friendly, being thick, honey-like resins and were not varietal specific. As mentioned earlier, things have changed and now a new line of hop extracts have been developed with the beta acids removed, allowing for a much less viscous substance. Typically you will see them labeled as “flowable” or with similar phrasing. CO₂ extracts are now commonly varietal-specific as well, so brewers can hone in on certain traits coming from the hop’s profile for later kettle additions. Just note that it’s typically advised not to add these CO₂ extracts with less than 10 minutes remaining in the boil.

Supercritical CO₂ Aroma Extracts

With specialized processing after the CO₂ extraction, you will find extracts that are further refined by selecting specific fractions of what is extracted from the hop. The primary fraction, discussed above, is the alpha-acid fraction. But the oil fractions are capturing the attention of brewers these days because they offer another way to add hop aroma to beer. Fractioned aroma extracts are usually recommended for use just prior to or in the whirlpool, or in the fermenter as a dry hop substitute or companion (use is product dependent). These may or may not come varietal-specific and will not contribute bitterness from alpha acids or polyphenols that whole-cone and pellet hops will release because of the extraction process, nor will they cause hop creep. Several of these are available from suppliers in homebrew-sized packaging.

Distilled Hop Oils

The availability of hop oils to homebrewers and commercial brewers has increased dramatically over the last few years and now includes distilled oils. These are another class of hop products with several sub-types and some crossover with the fractioned extracts. Alcohol extracts and steam-distilled extracts are the two main families, and within each are several sub-categories, like we see with supercritical CO₂ extracts. Some of these can be extremely potent and need to be handled with care. One line of hop oils boasts adding wet-hop character (freshly picked hops) to the beer. 

If available, follow the manufacturer’s instructions when using these products. But many suppliers of the distilled oils provide little instruction aside from performing bench trials prior to use and some loose dosing guidelines.

Depending on the supplier, fractionated extracts and distilled oils are blended to create aromas associated with different hopping methods. Kettle hop, late hop, whirlpool, and dry hop are examples of some of the descriptions used for fractionated extracts. Because these aromas approximate hopping practice, many commercial brewers use extracts to augment traditional hopping practices to improve process efficiency while minimizing obvious differences.

Written by Dave Green