By Mark Bowers
Seriously, What are Hops?
What exactly are hops? Why do brewers all around the world add them to beer? And why does it seem like everyone and their uncle is smitten with them? When I was growing up before I could legally drink beer (I won’t tell you when but it was a while ago) the only beers available in the US were a dozen or so macro lagers–beers brewed in batches large enough to fill inground swimming pools. I very distinctly remember radio ads expounding on the fact that Drewrys lager beer contained Fuggle hops.¹ I initially thought that the name and spelling were mistakes: shouldn’t it be Fugle or Bugle? What the heck is a Fuggle? What are hops and why would you put them in beer? And what exactly is beer anyway? Of course I was only about six years old at the time. My mom didn’t know either so I was left wondering about it for another ten years at which point I started to home brew. Suddenly a whole new world was opened up to me.
Among the many things I learned early on is that the vast majority (probably >99.9%) of beer made in the world today consists of just a handful of ingredients, which include malted barley, some other cereal grains like corn or rice, water and hops, and perhaps most importantly yeast to carry out fermentation. Water typically makes up over 90% of beer followed by less than 10% barley and grain derived components (including alcohol) and less than about 0.1% hop compounds. However, that last approximately 0.1% contributed by hops is vital to the production and shelf-stability of beer!
Let’s begin with a brief lesson in hops and exactly what they are. Hops are the flowers of a climbing plant that is in the family Cannabaceae, which also contains hemp and cannabis. The Latin or scientific name is Humulus lupulus. The family name Humulus likely came from the old German word “humel” or “humela” meaning “fruit-bearing” whereas the species name lupulus derives from the Latin diminutive word for “wolf,” as the hop plant was erroneously thought to strangle other plants as it climbed on them; think of hops as wolves among flocks of sheep. The English word hop probably comes from the Noregian word “hupp” meaning tassel (a description of the hop flower no doubt) or the Anglo-Saxon word “hoppan” meaning “to climb.”
The hop plant is technically a bine as compared to a vine. The difference between the two is that bines twist or twirl around a support in a helix (clockwise in the northern hemisphere and counter-clockwise in the southern hemisphere) as it climbs following the path of the sun during the day. Comparatively vines use suckers or tendrils to directly attach to their support while growing. Hop plants are perennials and produce one crop of hop flowers or hop cones per season typically harvested in late summer. The hop cones look somewhat like small paper pinecones. Inside the hop cone at the base of the petals lies a yellowish resin that is called lupulin. This resin is where nearly all the goodies, as far as brewers are concerned, reside.
How Did Hops Get into Beer?
Hops have likely been used by humans since prehistoric times. Before using hops in beer, hops were put into salads where the hop’s young shoots were consumed somewhat like asparagus. They were also used in medicines as a sedative and sleep-aid among other uses. Putting them into beer appears to be a much more recent occurrence. Early evidence suggests that hops were likely cultivated and used in brewing in Switzerland and France between the sixth and ninth centuries. The earliest known written evidence is from the Abbot Adalhard of Corbie who in 822 A.D. wrote several statutes indicating that the monastery used hops in brewing. How they were used in brewing beer early on is still a mystery. It was another 300 years before the writings of Abbess Hildegard of Bingen (ca. 1155) provided a more detailed explanation of how hops were used. In her text Physica Sacra (The Physical World) she described that hops were boiled in wort (unfermented beer). Boiling hops led to efficient extraction and formation of its bitterness plus some other flavors, notably spiciness. She determined that it required an hour or longer to efficiently make and extract the bitterness from hops. As fires at that time were stoked with wood that had to be gathered laboriously by hand it was not an obvious choice for early brewers to boil their wort with hops for a long period of time. This clearly was an important step and is even referred to as a disruptive technology.
About the same time that Hildegard was writing her text, commercial hop cultivation was taking off, first in Northern Germany, supplying hops to the breweries of towns of the Hansa region. This is probably the earliest region that was exporting hopped beer from about the 13th century.
However, before hops were commonly used in beer much of the beer in Europe in the Middle Ages was flavored with gruit, a mixture of herbs and spices that was kept secret by each town and taxed. Beer made without added flavorings is typically described as too sweet, even cloying making it less refreshing as a drink. At least some of the gruit components likely had some bitterness, which would help cut the sweetness of the beer in addition to adding other pleasing flavors.
Adding hops to beer shared similarly desirable outcomes to adding gruit; hops add both bitterness and other flavors to beer.² Despite the fact that hops gradually won out over gruit, it took centuries for this to occur as hopped beer slowly spread out from Germany, France and Switzerland. There were likely several advantages of using hops. As mentioned hops had a preservative effect. This not only produced beers that lasted longer it also allowed brewers to brew lower strength beers that lasted longer making them less expensive to produce and sell. Brewers had long known that the stronger the beer, in terms of alcohol, the longer the beer would last. However, strong beers were more difficult to make and cost substantially more. The tax on gruit was higher than it was on hops, and even though the taste of hopped beer was different from gruit flavored beer — probably more bitter, and was likely an acquired taste — hopped beer would eventually become preferred to gruit and other flavored beer.
In time not only did hops win out over gruit and other flavorings, in some places hops became the only legal flavoring for beer. In the 14th century several towns in Germany had edicts stating that only barley, water and hops can be used to brew beer. This culminated in the 1516 Reinheitsgebot ruling allowing only barley, water and hops in beer for all of Bavaria. Eventually as all of Germany became united, the Reinheitsgebot became law throughout the country and is still in play even today.
Early Domesticated Hops
From early on farmers and brewers recognized that some hops produced better beers than others. Hops like most plants have proliferated into countless different subspecies as they evolved and adapted to various environments. As early as over 700 years ago, local governments were trying to protect their species of hops from being used by others. For example, in the fourteenth century Emperor Charles IV issued a law making the export of hop cuttings (a means of propagating hop plants) from Bohemia a crime punishable by death.
For hundreds of years, there were only a handful of hop types that were used in brewing–and there were essentially no organized breeding programs for developing and selecting new hop types. During this period although people recognized that some hop types were better than others, their characteristics were all very similar. Consequently, these hops were effectively viewed as interchangeable when it came to brewing. The four European continental hop types that were dominant in brewing on the main land were called the noble hops and consisted of Saaz (Czech Republic), Hallertau, Tettnang and Spalt (last three hailing from southern Germany). Their characteristics are usually described as earthy, woody, spicy and herbal and can even have delicate floral aromas. Even today, good sources of these hops are sought after and find their way into almost all of the traditional lagers of Europe. They are also used extensively in the traditional ales of the continental countries such as Belgium, France, Netherlands, and Norway.
Meanwhile, in the other major brewing region of the world, the United Kingdom, they had their own hop varieties originally cultivated from local wild species, including Fuggle and Goldings, with East Kent Goldings being especially revered. Some sources refer to these as “nearly noble hops” along with two lesser continental hops, Styrian Goldings (actually a Fuggle variety) and Hersbrucker. They are similar to the true noble hops but just not close enough to make the cut. These two hops are what give British ales such as bitters their characteristic flavor.
Hops Evolve with a Helping Hand
Noble and near-noble hops were the main hops used in brewing for centuries, with the majority of early commercial hops being wild hops that were cultivated and scaled up; there was no systematic selection of hop types. In Stan Hieronymus’ now seminal book For the Love of Hops he quotes Val Peacock, a hop researcher at Oregon State University, who somewhat facetiously stated that hop variety selection process was non-scientific and subjective, saying “we like the hop that grows on this side of the road; we’re not so happy with the hop that grows on that side of the road.” Besides flavor and aroma attributes, practical agricultural aspects were just as important. Hop farmers needed good yields of disease and pest-resistant hop plants. So selecting hop plant varieties was and continues to be a multi-attribute exercise, despite Peacock’s pejoratives.
Let’s return to the Fuggle variety that so captured my attention when I was a kid. It’s history is one that contained some mystery that was just recently revealed. Fuggle, along with the Golding hop, is a favorite hop of British brewing and has been extensively and successfully used in several hop-breeding projects. This story was first written by professor John Percival of the South-Eastern Agricultural College in the UK in 1901 and was recently updated by Lionel Burgess, a local historian from Horsmonden, UK.
So the story goes: sometime in the early 1860s, Sarah Stace, after coming home from picking hops at her nephews’ hops fields, emptied her dinner basket in her flower garden. Unbeknownst to her, among the crumbs was a hop seed that had serendipitously fallen into the basket. The hop seedling, which appeared from the errant seed, was separated out and grown, and the hops from this plant were found to have exceptional properties. Sarah and her partner George Stace Moore brought the hop to their nephews Richard, John and Henry Fuggle, at whose hop farm Sara had been picking hops. They planted it and subsequently expanded its planting to many acres. The hop became so popular that in 1871 they auctioned off 100,000 sets of the new hop, which at the time was called “Fuggle’s Goldings”. Eventually, the Fuggle hop became so popular that about 78% of the total UK hops in 1949 and the majority of the US hops about that time were Fuggle.
Tune in next time for Part Two of Mark’s Story of Hops! Thanks for taking the hop-portunity to read!
Mark Bowers is the Brewmaster at Aeronaut. The views and opinions expressed on this web site are solely those of the original author, and they do not necessarily represent those of Aeronaut Brewing Co.
- It is interesting to note that Drewerys lager used what was a typical ale hop, Fuggles, and thought it was so special they put it in their advertisements. It was an extremely rare occurrence for any North American brewery to ever mention specific hop types to their customers.
- To get a better understanding for how little an amount of actual alpha acids are needed to be noticeable, 5 ppm, mg/l or IBUs, the detection threshold for iso alpha acids is similar in concentration to dissolving a single grain of table salt into a gallon of water and tasting it.
Stan Hieronymus, For the Love of Hops: The Practical Guide to Aroma, Bitterness and the Culture of Hops (Boulder, Colorado, Brewers Publication, 2012)
Tom Acitelli, Audacity of Hops (Chicago Illinois, Chicago Review Press, 2013)
Mitch Steele, IPA: Brewing Techniques, Recipes and the Evolution of India Pale Ale (Boulder, Colorado, Brewers Publication, 2012)
Martyn Cornell (November 20, 2009), “A short history of hops” Zythophile, retrieved from zythophile.co.uk/?s=hops
Mark Bowers (April 2, 2020), “History of the India Pale Ale” , Aeronaut Blog, retrieved from aeronautbrewing.wordpress.com/2020/04/02/history-of-the-india-pale-ale/
Mark Bowers (April 18, 2020), “History of the New England IPA”, Aeronaut Blog, retrieved from aeronautbrewing.wordpress.com/2020/04/18/history-of-the-new-england-india-pale-ale/