The aromas associated with hops come from their essential oils (next section), and these oils contain roughly 500 different chemical compounds that have been identified so far. Many exist in only the barest of trace amounts, while others, such as myrcene, can make up 50% of the total essential oil content. The interaction of these compounds is very complex. Brewing scientists have attempted to recreate the aroma of a particular hop by combining the primary individual oils in the appropriate proportions and failed miserably. Of course, there is nothing wrong with adding hop oils to a beer to enhance its hop character, but the whole of hop aroma is greater than the sum of its parts.
Hop flavor is a combination of hop bitterness, resin (mouthfeel), and aroma. Hop aroma from the essential oils is hard enough to describe; flavor is much more difficult. Suffice to say that midvarieties dling short boil times that contribute a combination of isomerization and residual oil and resins to the wort can be perceived as flavor in the final beer. Generally, these are boil times of less than 20 minutes. Hop steeps, where the hops are soaked in hot wort before cooling, will also contribute hop flavor to the beer.
The following lists seven primary characters that are often used to describe hop aroma: floral, fruity, citrus, vegetal, herbal, resinous, and spicy. Of course, this listing is subjective, and if you ask three different experts you will get three different lists. Some characterization plots break the aroma down into 12 or more different characters, but these seven get the point across. It is important to understand that aroma is subjective, and different people can perceive a particular aroma differently. For example, some people might describe mint as herbal and others would describe it as spicy, and they both would be correct.
For more discussion of the essential hop oils, see Stan Hieronymus’s book,
Aromas of the Main Essential (Aromatic) Oils Found in Hops
Mycene: Sweet carrot, celery, green leaves
Humulene: Herbal, woody, spicy clove
Caryophyllene: Spicy, cedar, lime, flora
Farnesene: Woody, Citrus, Sweet
β-Damascenone: Honey, berry, rose, blackcurrant, concord grape
β-Lonone: Raspberry, violets
Linalool: Floral, lavender
Geranol: Floral, rose, marigold, geranium
Nerol: Floral, wisteria
Citronellol: Citrus, lemon, citronella oil
Terpineol: Citrus, fruity
Humulenol: Spicy, pineapple, cedar, sagebrush
Humulol: Spicy, herbal, hay
4MMP2: Muscat grapes, blackcurrants, onion
Categorization of Hop Aroma
Floral: Geranium, Rose, Jasmine, Lily of the Valley, Lavender
Fruity: Apple, Berries, Peach, Melon, Passion Fruity
Citrus: Grapefruit, Orange, Lemon, Lime, Bergamot
Vegetal: Celery, Tomato Leaves, Green Pepper, Cabbage, Hay
Herbal: Tarragon, Marjoram, Lavender, Dill, Sage<
Resinous: Pine, Juniper, Heather, Tobacco, Woody
Spicy: Fennel, Black Pepper, Nutmeg, Clove, Mint
Hop Variety Categories
Today, hops are cultivated in many different countries. European, English, American, and Pacific hop varieties are readily available on the open market. In addition, there are Chinese and South African varieties as well, but these are seldom seen outside of their own regions due to high domestic demand. The European varieties were the original brewing hops, and these are often referred to as “landrace” or “noble” hops. These early hops have delicate floral, spicy, and resinous aromas that for centuries were the definition of what hops should smell like. The English varieties developed next and these have traditionally had more of an herbal, earthy, and fruity aroma compared to the European varieties. The American varieties have a predominately citrus character, with undertones of herbal, resinous, and spicy aromas. The Pacific varieties (i.e., New Zealand and Australia) have a strong tropical fruit character with citrus and floral notes.
There was a time when each region could be described by one word: European, spicy; English, herbal; American, citrus; and Pacific, fruity. But, with the craft beer movement accelerating since the early 1990s, hop breeding and development has exploded. Today it is common to find German varieties, such as Mandarina Bavaria and Hüll Melon, that smell of fruit; American varieties, such as Citra and Mosaic, that smell tropical; and English and Pacific varieties that smell like citrus. There are some hop varieties that help define particular styles, such as the minty flavor of Northern Brewer for California common beer, the floral character of Spalter and Hersbrucker for German lagers, Cascade for American pale ale, and Fuggle and East Kent Goldings for British pale ale. As you are learning to brew, and learning what defines the character of particular beer styles, you will probably attempt to brew classic recipes faithfully by using the prescribed malts, hops, and yeast, and that is a good idea. If you want to get a great foundation in brewing and tasting different beer styles, I heartily recommend brewing all of the recipes in Brewing Classic Styles by Jamil Zainasheff and John Palmer.
However, one of the first substitutions any brewer will make is for a hop that is not readily available, or for one that they just don’t particularly like. In fact, I would suggest that new brewers consider the hop callouts in any beer recipe to be mere guidelines for a couple of reasons. First, because bitterness is bitterness—there is very little difference in the flavor of that bitterness across different hop varieties. Now, that being said, the flavor and aroma hop selections of a recipe are a bit more important, because the dominant character of those hops may indeed be characteristic of the style. There is still room for substitution though within that hop’s variety category. For example, if a recipe for American pale ale calls for Cascade, a good substitute would be Centennial or Amarillo.
If you need to substitute for German Tettnang in a German Pilsner recipe, you could readily use Spalt Select or Saaz. Don’t be afraid to substitute hops, just be reasonable about it. You would probably not want to substitute Cascade or Chinook for a German hop if you are trying to faithfully brew a German Pilsner style, because the characters are just too different. But brew what you like; everyone’s flavor preferences are different, some prefer fruity, others prefer floral, and still others prefer resinous. Gradually you will find the hop varieties you prefer, and as you fine tune your favorite recipe(s) you will probably decide on particular hops that have to be in there. That’s the purpose of a recipe.
The following lists some common hop varieties and suggested substitutions. I used to try to keep this book up to date on all varieties, but the hop world is moving far too fast. Get online and find out what’s new.
European Hop Varieties:
General Character: Floral, Spicy, Resinous
Substitution: European-Like: Hallertauer Mittelfrüh, Tettnang, Spalt Select, Saaz, Hersbrucker
Substitution: English-like: Magnum, Opal, Merkur, Smaragd
Substitution: American-like: French Triskel, Hallertau Blanc
Substitution: Pacific-like: Hüll Melon, Madarina Bavaria
English Hop Varieties
General Character: Resinous, Fruity, Spicy
Substitution: European Like: Target, Challenger, Northdown, Progress
Substitution: English-like: East Kent Goldings, Fuggles, West Goldings Variety, Sovereign
Substitution: American-like: Admiral, Pioneer, Epic, Pilgrim
Substitution: Pacific-like: Arucher, Olicana, Jester
American Hop Varieties
General Character: Citrus, Herbal, Resinous
Substitution: European-like: Crystal, Mt. Hood, Horizon, Cluster, Wakatu
Substitution: English-like: Glacier, Columbia, Willamette, Gelena
Substitution: American-like: Amarillo, Cascade, Centennial, Ahtanum
Substitution: Pacific-Like: Mosaic, Cita, Simcoe, Amarillo
Pacific Hop Varieties
General Character: Fruity, Citrus, Floral
Substitution: European-like: Helga, Pacifica, Sylva, Ella
Substitution: English-like: Green Bullet, Fuggle, Wye Challenger, Pacific Gem, Super Pride
Substitution: American-like: Dr. Rudl, Walmea, Sicklebract, Galaxy
Substitution: Pacific-like: Nelson Sauvin, Rlwaka, Motueka, Topaz
Note on using the above section: Hops are arranged according to region of origin and principle characters. Hops may be substituted within a subgroup, and across the categories in the same row. Have fun exploring the similarities and differences!
More from How to Brew:
How to Brew: Everything You Need to Know to Brew Great Beer Every Time by John Palmer. Copyright 2017 Brewers Association. Reprinted with permission from the publisher; all rights reserved by the original copyright holder.