Hops have been used to flavor beer for about thousands of years and about 500 years ago they became the dominant bittering and flavoring herb used in brewing. Hops have a lot of characteristics brewers take advantage of to brew great beer. Not only do they give a great aroma and a bitter bite to your beer, but they also have great antiseptic qualities that keep your beer fresh and drinkable much longer.

Today hops look very different than they did back in the year 900. All these great properties hops have and all the hundreds of varieties of hops that exist today are all thanks to one scientific process called selective breeding.

How growers select hop varieties to breed

The US hop and brewing industries are larger than ever. With all that growth the demand for hops has never been higher. Both for traditional varieties and new hops that push the envelope of aroma and bitterness. With hundreds of varieties of hops out there how do growers and brewers choose the traits they want in their hops as they breed them? Well, there are three main considerations hop growers look for when it comes to breeding a new variety of hops.

• How well the individual plants tend to grow?
• If they tend to get diseases?
• What flavors and aromas do they bring to a finished beer?

Choosing the right variety of hop

When it comes to how well hops grow there are a lot of things to consider for growers. Does a particular plant require more water and space than another? How tall does the vine grow and does it fit nicely in their existing trellises? How many hop cones are produced by one individual plant on average? Do the hop cones mature at the right time of the year? Do the hops succeed in the local microclimate? All these are considerations breeders are looking for when trying to select plants to breed together. Even things like are the hops easy to pick once they are ripe are considered.

Making sure the hop variety is resilient

Hops are not the most robust crop out there. They are pretty susceptible to insects, pests, and mildew spoiling those delicious green cones. Crop losses both chronic and catastrophic are a fairly common occurrence for growers especially compared to other crops. Between disease management costs and crop damage about 15% of the hop, crop value is lost every year. To brewers and drinkers, this means higher beer prices and sometimes not getting the shipment of hops you were expecting. Meaning lost revenue for both growers and brewers. In addition as the world’s largest hop producer crop damage can really hamper an important export of US agriculture. So growing hops that are more resilient to damage and disease is incredibly important for keeping the beer flowing and keeping beer costs down.

Selecting hops with certain properties

Finally are all the great flavors that robust hops bring to the table as brewers have continued to push the envelope of how much flavor can be packed into a beer. Consumers in the US have gotten a mighty appetite for hops. American beers are generally known for their aggressive hop profiles which bring a great aroma. These bitter and aromatic hops define the American craft beer community and bring a lot of flavors.

How selective breeding is actually done

Male and female hop flowers are found on separate plants. Female hop plants produce the cones we use for brewing. To produce a new variety you need both a male and a female plant. When selecting a female parent you’re looking for two out of three traits. Because the female plants are the only ones that produce cones for brewing they must grow well and mature on time. Picking your best female plants tends to be much more important than picking the best male hop plant.

On the male side we are really only looking for disease resistance. Whether or not they grow as tall or mature too quickly isn’t really a problem as we are only looking to harvest their pollen for later use. As such the most important aspects growers look for in male hops to pass on in the next generation are durability and disease resistance.

So once you have picked a lovely couple of hop plants you’re ready to begin breeding them. It’s time to grab some pollen from a flowering male plant and put it on the newly formed hop cones of a female plant. Most of the time this is done by hand as it ensures more seeds will form in the pollinated hop cones. In nature hop pollen spreads with the aid of the wind. Males shed their pollen all over the place and the wind carries it and deposits it on females nearby. This can often happen in commercial hop yards if you keep too many hop plants around. And since hop cones full of seeds make bad beer male plants are often put under wraps by growers.

Getting a new variety hop plant

It usually takes a hop plant several growing seasons to establish enough of a group place for the plant to feel comfortable producing cones. And if you want to assess things like maximum yield and tolerance to different weather conditions you’re going to need at least 5 years of data.

Because of this rather long timetable and years of time and resource investment with risk with not a lot of return most growers don’t experiment with hop breeding. It seems breeding hops is mostly done by extremely large growers or university agriculture programs. That is why the Brewers Association has signed an agreement with the US Department of Agriculture to fund public hop breeding yards to release disease-resistant aromatic hops into the public domain. That way any great hops created by this trust can be grown and brewed by anyone.