Creating New Hop Varieties
Ever wondered where your hops come from? You might know where they are grown, but what do you know about their origin? Many varieties used today were invented to enhance the best traits of several breeds.
Suppose you’re tasting your latest beer and you decide the hop nose you gave it is wrong. Not too spicy, exactly. Not too grassy. Not floral, either. That’s not it.
You want a hop that has a flavor that’s different than anything on the market, maybe between Cascade and Centennial or between Mt. Hood and Columbus. New hops are developed regularly. Can someone create one to satisfy your need?
In fact many of the hop varieties that are considered standards in the brewing industry today are relatively recent inventions. Mt. Hood made its commercial debut in 1990. Liberty first appeared on the market in 1991. And if you’ve ever wondered why none of the brews you drank when you first came of age had that trademark Cascade flavor, its because Cascade hops barely existed. They hit the commercial market in 1972, but at that time more than 80 percent of the hops planted in the United States were Cluster, and Cluster continued to dominate until the mid-1980s. A brewer who didn’t use Cluster used an established import such as Fuggle, first grown by the British in the 1860s, or Brewer’s Gold, which first appeared in 1919.
So who decides what hop varieties make it to market? And who decides what the goals are when the horticulturists start experimenting?
Well, if you want to have a say in the process, it helps if you work for a big brewery. Much of the funding for public hop-breeding programs comes from an organization called the Hop Research Council. It consists of six very large brewing companies: Anheuser-Busch, Adolph Coors, The Stroh Brewery Co., Suntory (Japan), Heineken (The Netherlands), and Labatt (Canada).
Virtually all the US hop dealers belong to this organization, and the growers are represented through their state commissions. The HRC directs how money is to be spent among the researchers.
The only public breeding programs in the United States are located in Corvallis, Ore., and Prosser, Wash. These public programs, which receive state and federal funding in addition to money from the HRC, have most recently been involved with finding new aroma hops but in the past were responsible for many of the high- or super-alpha hops available today. Hops that are released from the public programs can be used by any hop grower.
There are also some private breeding programs operated by hop dealers. These top-secret programs develop hops that are patented and only grown and sold at the direction of the dealer who bred them.
So will anyone be producing your ideal hop? Only if it passes muster in the intense world of hop breeding where at most one in 10,000 hop varieties makes it into a glass.
Beneficent Mutation
New hop varieties are bred to accentuate a positive trait (increase alpha acid, for example) or decrease a negative trait (such as the hop’s susceptibility to a particular disease). In nature hops reproduce either by pollination of the female, which develops a seed, or by the roots (rhizomes) forming runners that spread out and emerge from the ground creating new plants away from the main plant.
In a typical commercial hop field, only female hops of one variety are grown. The female develops the hop cone that we have come to know and love in brewing. This cone can possess up to 10,000 lupulin glands, which contain the hop resins and oil profile used in the brewing process. The male flower, on the other hand, only produces 10 to 25 such glands and so is useless for brewing purposes.
Because of this controlled planting, you can’t expect random acts of inter-variety breeding to create the next big Cluster or Cascade. New varieties are produced in three basic ways. The first is by mutation or by natural selection. Beneficial mutation doesn’t happen very often, but some famous hops have been discovered this way, such as the variety Bates, a type of Cluster.
Mass Selection
The second method of producing a new variety is by mass selection. In this process you would cross many plants, either in a controlled or uncontrolled fashion. Controlled means you know both parents. Uncontrolled means you don’t; you just cross plants, test the results, and cross your fingers. Examples of hops coming from a controlled program are Nugget, Olympic, Chinook, Centennial, and Cascade. Some uncontrolled offspring are Eroica and Galena.
While it may sound easy, it is actually very difficult to get new, commercially viable varieties through mass selection. At Hopunion USA, a private grower and hop dealer, more than 10,000 cultivars were crossed a few years ago, but only one (Columbus) has made it all the way through the program. To date only a half dozen are still being evaluated for their characteristics. The remaining crosses show some promise. The other 9,900-odd crosses were destroyed.
Just because two types of hops were crossed, that doesn’t mean the resulting plant will have the characteristics of the parents. Chinook is a good example of a crossed hop that differs from its parents. Chinook’s parents are Petham Golding and Brewer’s Gold. You might consider using Chinook in place of Brewer’s Gold for bittering but would not substitute it for the Golding as a finishing hop. On the other hand Chinook is a popular hop both for bittering and finishing in its own right.
Brewer’s Gold and Bullion are products of the first formal mass-selection breeding program. The program’s goal was high alpha-resin content and eventually tests also produced Northern Brewer. High alpha-resin hops grown today are descendants of this original program.
Chemical Inducement
The third way to breed hops is by chemical inducement. Most hops are called diploids because they have two sets of chromosomes. A chemical is used to create a tetraploid hop, one with four sets of chromosomes. Then the tetraploid is crossed with a diploid to create the final product, a triploid hop. The goal of a commercially grown triploid hop is to create a female who acts like she is pollinated (and develops a bigger cone to house the seeds, thereby giving bigger yields) but is in fact sterile. The result is bigger yields without all the seeds of pollinated hops. The seeds are undesirable because they lower the harvested hop’s value.
The Willamette variety is a triploid version of Fuggle. Mt. Hood, Crystal, Ultra, and Liberty are triploid Hallertauer varieties. A few commercial triploids have occurred in nature, such as Hueller and Record.
Making the Hop Grade
There are many reasons that hops don’t make the grade in a breeding program. In the United States breeders are primarily looking at yield and resistance to diseases, mainly downy mildew. If the yield is too low, then the cost of growing the variety may be too great. Yield may also be subject to great variations from year to year, thus making it difficult to ensure a normal flow of supply to the brewer.
While downy mildew is the main disease that the US breeder initially looks for, other diseases and pests can eventually play an important role in a new variety’s future or demise. A few years ago Hopunion had a variety called CFJ4 that was an instant favorite with many of the craft brewers. Unfortunately CFJ4 wasn’t resistant to mosaic virus and had to be irradicated after a few years. Breeders don’t test for resistance to this virus.
This year US hop growers had their first official outbreak of powdery mildew, which has damaged portions of the crop. Certain hop varieties appear to be more susceptible to this disease than others. Because the US breeding program has never taken powdery mildew into consideration, no one really knows which varieties are immune or not and if so to what degree. This disease will most likely be here to stay, so in the future hops will be tested for it.
There are many other reasons that a hop doesn’t make it through the breeding program or is terminated once trial production starts.
Inappropriate maturity cycle: Hop harvest usually begins around the 18th of August and goes through the end of September. If the hops were mature in mid-July, it would be difficult and costly to assemble a crew to pick them. If a hop variety matures unevenly, some plants will have cones that mature early, while other cones on the same plant are just in the burr or beginning stage. This affects yield, aroma, and acceptability in the harvested hop.
Poor aroma: There was once a test plot that smelled like garlic as you walked through it. A breeder will automatically eliminate hops that have an unappealing aroma. This is a very subjective area in the reeding programs.
Unacceptable resin/oil content: The hop may have unacceptably low alpha or oil content. In this case there is no need to look any further. Sometimes the cultivar may be discarded for having too much oil, but hops aren’t discarded for too much alpha resin.
High cohumulone content: Large commercial brewers seem to favor hops with a low cohumulone (a component of alpha acid). Therefore, the breeder automatically has a prejudice against any hop showing a high cohumulone. Some brewers feel that a high cohumulone imparts a harshness to the beer, though others dispute this. There are some hops that have a higher cohumulone content, such as Galena, that are grown commercially.
Brittle plants: A brittle hop stalk may break easily in the wind or from tractors. In this case the attached cones will die. Brittle plants in the picking process will cause problems separating the cones from their vines.
Hard or misshapen cones: Cones that are prone to shatter in the picker can’t be easily separated from the other material and are therefore lost. The cones might be very hard to pull away from the vines, so too much of the leaves and stalk material are gathered, leading to a “dirty picked hop.”
During the picking process some leaf and stem material comes off with the cones. Part of the cleaning process involves short, angled conveyor belts. As the hops, leaves, and stems go over these belts, the round cones roll backward off the forward-moving belts. The flat leaves and stem material stay on the belts, thus separating this material from the cones. This leaves a clean product to eventually put into bales. A cone that is too square makes this process difficult if not impossible.
Tendency to oxidize: The hop may be subject to extremely rapid oxidation or deterioration.
Breeder bias: One big reason that a hop can be discarded is the bias of the breeder. Breeders are usually looking for particular qualities in specific breeding programs and will automatically irradicate any hop not meeting the criteria. An example is the Willamette hop, which was bred to be like a Fuggle. Undoubtedly the breeder had many crosses in the program that didn’t smell like Fuggle. Even though they were brothers and sisters to the Willamette, they were eliminated from the program. Some of the eliminated hops may have been quite nice, but the breeder was only interested in finding a hop similar to Fuggle at the time.
Brewery favorites: Finally, even if a potential new hop meets all the positive qualifications that a breeder is seeking, the hop must be approved by the brewers to use in making beer. Otherwise there is no reason to grow it. If a hop, say your ideal hop that’s between Cascade and Centennial, catches a brewer’s attention, it can be grown on test plots and delivered to the brewer for further evaluation. But that doesn’t mean you’ll be able to buy it at the homebrew supply store anytime soon. This process can take many years.
It was historically the case for a hop to take at least 10 years to go through the complete process of breeding and evaluation before becoming a commercially grown variety. Today this can happen a little faster, but it can still take years. At the end of the testing by brewers, many hops still end up being discarded. The lucky few will go on to be grown commercially and will eventually make it into your beer.
