Many homebrewers and craft beer enthusiasts are familiar with the term “Noble Hops” which refers to four varieties of continental European hops originally grown in Central Europe. The four hop varieties are Hallertauer, Saaz, Spalt and Tettnanger.
The four traditional varieties of noble hops are properly characterised as aroma hops, because they have relatively low alpha bitterness, but are highly aromatic. They are widely used in traditional continental beer styles including Bohemian Pilsner, Dunkel, Oktoberfest/Marzen and many Wheat/Weizen beers and other lagers.
From a hop analysis view, these hops have high amounts of the hop oil Humulene (Humulus Lupulus). Humulene is a fragrance often used in the perfume industry with an aroma that has a robust earthy, woody and herbal character. Oxidation, heat and light rapidly break down humulene, which is why noble hops are susceptible to degradation if not properly stored. Relatively low alpha acid levels (generally 3% - 5.5%) add aroma and bitterness without becoming harsh. The low amounts of harsher tasting beta acids (Adlupulone, Colupulonel & Lupulone) contribute to the desirable flavour of noble hops. Many also have a slightly spicy finish which adds to the character of beers like Pilsner.
Outline Biology
Hop cones contain c.40% to 50% cellulose, c.15% protein, and c.10% water, but it is the alpha acids (from c.2% to occasionally 20% plus) and essential oils (as little as 0.5%) that interest brewers and beer connoisseurs.
Components of Hop Oil
Myrcene (54 %)
Humulene (22 %)
Caryophyllene (8 %)
Farnesene (6 %)
Growing soil and conditions have a large effect on the finished hops. Wine enthusiasts understand the concept of terroir (land), which is the idea that the area in which a grape is grown is as important as the grape variety itself. It’s why Malbec does so well in Argentina and Sauvignon Blanc thrives in New Zealand. A New Zealand-grown Malbec may still taste great, but it won’t be the same as South American examples. Perhaps not surprisingly, the same principles apply to hops.
Noble hops are classic European varieties that are responsible for the signature flavours of pilsner and other Continental lagers. The four noble varieties are:
Hallertauer Mittelfrüh
Saaz
Spalt
Tettnanger
Hallertauer Mittelfruh (Hallertau)
Named after the Hallertau (Halledau) region in central Bavaria, it was widely grown in Bavaria until the late 1970’s when it was largely replaced by the Hersbrucker variety. A fungus called verticillium ravaged the Hallertau hop crop at that time. You will often see Hersbrucker sold as “Hallertauer Hersbrucker” though it is actually a Hersbrucker variety. Later Hallertauer Gold and Hallertauer Tradition variants (Also Hallertauer “Magnum, Merkir and Taurus”) were developed from Hallertau that were more disease resistant. The hop has a highly floral character, slightly earthy but without a very strong spicy flavour. It is used in both German and American lagers, and is known as a key flavour/aroma hops for Sam Adams Boston Lager. Substitutes include Hersbrucker, Mount Hood and Liberty.
Saaz
Saaz is a hop traditionally grown in Bohemia and the modern day Czech Republic where it accounts for c.65% of hop production in the region. It is named after the Czech city of Zatek, which in German is Saaz. It has a distinct flavour that is mild, earthy yet spicy. It is the definitive hops used in Pilsner Urquell and Budvar, which are the basis for almost all of the most popular American lagers. However Saaz is also widely used in all types of lagers, pale ales, wheat beers, and many other continental styles. Its closest substitute is a hop called Sladek, though often Tettnanger, Lublin, Ultra or Sterling may be used.
Spalt (Spalter)
A traditional hop from the Spalter region of Germany south of Neuremberg. It is grown in a fairly small acreage and not as widely distributed as other noble hops making it somewhat difficult for home brewers to obtain. It provides a mild, slightly spicy flavour with a strong noble hop aroma. Note that Spalt is not the same as the more widely distributed “Spalt Select” which is actually a descendent of Hallertauer Mittelfruh. Spalt is used in many traditional German styles including Alts, Bocks, Lagers, Pilsners and Munich Helles. Substitutions include Saaz and Tettnanger.
Tettnanger (Tettnang)
This is a hop from Tettnang, which is a small town in Southern Baden-Wurttemberg Germany. It has a mild, slightly spicy, floral character and is genetically similar to Saaz grown in the Czech republic. It is highly valued as both an aroma and flavour hop and is exported worldwide for use in Belgian ales, BocksFrench ales, Lagers, Pilsners and Wheat beers. Substitutes include Saaz and Fuggle hops.
Summary
Having been cultivated in specific regions for hundreds of years, noble varieties express terroir much more apparently than cultivars with shorter histories. In fact, the names of the noble hops themselves are identical to the regions in which they were developed.
This can lead to some confusion. Take Tettnang, for example and as previously stated. Tettnang is the name of a town in the German state of Baden-Württemberg. It’s also the name of the hops variety that is grown in and around that town. In German, Tettnanger means something or someone from Tettnang, just as a Düsseldorfer comes from Düsseldorf and a Berliner from Berlin. So far, so good.
But Tettnanger hops are also grown in the Pacific Northwest of the United States. This variety was actually propagated from hops growing near Sankt Gallen, Switzerland, which is on the other side of Lake Constance from Tettnang, Germany. If you were to purchase American-grown Tettnanger when you actually wanted the true noble variety, you’d probably be disappointed.
To help distinguish the authentic varieties when they’re grown in their regions of origin, growers sometimes prefix the cultivar’s name with the area in which the hops were actually grown. So if a supplier carries both American Tettnang and Tettnanger Tettnang, then you know that the former is a Tettnang hops that has been grown in the United States, while the latter is a Tettnang hops grown in its birthplace.
The table below indicates the four classic noble hops, common names for the authentic landrace cultivars, and potentially confusing varieties that might be carelessly labelled. This isn’t to suggest that great beer can’t be made with these other varieties, but rather that brewers need to know this information when selecting ingredients.
The “Nearly Noble” Hops
In addition to the four hops listed above (and their variants), you will often hear of other hops occasionally listed as noble hops. These include English Fuggles, East Kent Golding, (Hallertauer) Hersbrucker, and Styrian Goldings (a Fuggle variant). While none of these are actually true noble hops, they share many of the noble hop characteristics of being highly aromatic and having low alpha acid.
Also due to the pressure of land usage in Central Europe, diseases, crop pests and the move of many commercial brewers towards high yield, high alpha hops (for hop extract), the supply of true noble hops has been steadily decreasing for decades. Growers are instead producing hybrids or variants such as Liberty (a cross of Hallertauer Mittlefruh with a disease resistant US hop) or Mount Hood (a higher alpha acid hybrid). Variants of the nearly noble hops above such as Willamette (derived from Fuggles) are also widely grown in the United States.
There are now over 188 varieties of hops grown worldwide, with new hybrids being continuously created in agricultural and horticultural research centres.
What are hops and how are they used?
Hops are the flowers of the hop plant. Hops are what add bitterness and flavour to all different kinds of beer. The female flowers of the hop plant are called cones because they look like soft green pine cones. Brewers need the dark yellow oil called humulene found towards the centre of the cone. Humulene is very aromatic essential oil from the hop flower and this essential oil is a base note, that is steam distilled from the strobiles of Humulus Lupulus. Its spicy sweet and herbal aroma is also used in calming blends in both perfumes and diffusers.. If you smell the whole cone, it’s just going to smell green, but once the cone is broken open and the oil is released, it becomes aromatic and you can really get a sense of the flavours that the hops will add to the beer.
How do hops grow?
Hops are typically grown on 5.5M (18’) high trellises, which maximises their growing patterns. This means the hops grow to the top of the wire trellis and then start to fill out at the right time of year to maximise their production.
Poles are placed into the ground with a cable running along the top of the poles and down the rows. Each of the cables has two strings allocated to each hop plant. The strings are tied at the top of the cable at one end and stuck into the ground right next to a hops plant at the other end.
The hop plant will grow up the string on its own, but the best practice is two weeks after planting, when the shoot is about 1M (3,3’)long and wrap the shoot counter clockwise around the string. As soon as the hop plant is started on the string, it will climb on its own. The hop plants follow the sun as it crosses the sky. They climb and then curl around the supports and can climb up to 0.3M (1’) daily.
At harvest the whole vine is cut down from the trellis on which it has grown and brought to a processing barn, where the hops are separated from the leaves by machine. Every vine is loaded individually into the machine on a chain that will drag it into finger picking drums. Finger picking drums are rollers that knock all the leaves and hops off of the vines.
There are seven different finger picking drums that the plants go through, followed by a series of fans positioned at different angles on the conveyors and these divide the hops cone from the leaves. Another conveyor takes the clean hops out and loads them to be dried. The last conveyor collects all the rope on which they have grown, along with the leaves for sustainable disposal practice.
Efficiency is critical to ensure the freshness of the hops as they go through the process of harvest, separation, drying, pelletisation and finally storage in the freezer, within 24-hours.
After the green hop cones have been separated, they need to be dried down, ground up and pelleted. Then placed in a vacuum sealed nitrogen flushed bags to protect them from oxygen and retain their freshness. This is typically the format that is used in the craft brewing process. There are fresh hop beers that use the whole cone dry or fresh. However brewers need to collect the hop cones on the same day they are harvested and begin brewing within 48-hours.
Hop Selection
With such a large variety of hops available, there is a myriad of opportunities for brewers to create innovative and new beer flavours. Hops are an essential part of the aromas and flavours created in craft beer brewing. Varieties can be combined, the quantities used are variable and also the way in which they are used in the brewing process varies. Hops can be introduced gradually, in varying quantities and at different stages of the brewing process, with each combination producing a different outcome.
Craft Brewing
Craft brewing is an artisanal process, a mixture of craft and science, created with something of the brewers personal signature and although hops are a very important element of the ingredient selection, they are but one. Grains, yeast, water and flavour additives all combine together in the brewers recipe to create the finished product.
Read more about craft brewing in our related blog articles.
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