The Art of the Brew: Exploring Hops and Other Plant Ingredients That Define Beer

T he modern brewmaster is a highly skilled professional who expertly navigates the intricate beer-making process. This role demands a deep understanding of chemistry, biology, and engineering, along with a mastery of key ingredients such as hops, malt, yeast, and water. Precise control over factors like fermentation and temperature is essential.

Yet, what truly sets a brewmaster apart is their profound knowledge of aromatic plants, cultural traditions, and sensory perception. This expertise fuels their creativity, allowing them to craft innovative recipes and flavors that elevate beer to an art form, essential to human civilization.

One of the most distinguished brewmasters is Garrett Oliver, the visionary behind Brooklyn Brewery since 1994. He is also the editor of “The Oxford Companion to Beer” (2011) and author of “The Brewmaster’s Table” (2003). Plantings recently visited Garrett at the Brooklyn Brewery to delve into his insights on human sensory perception, global culture, and how aromatic plants contribute to beer.

In this interview and the upcoming issues, you’ll discover what beer has to teach us about aromatic plants and our world.

Gayil Nalls: Beer is a cultural artifact shaped by the ingredients and traditions of different regions worldwide. How do you draw on different cultural plant histories and unique qualities of various plants in your brewing process?

Garrett Oliver: When we consider the ingredients in beer, it’s important to recognize the historical evolution of these components. For example, the use of spices in beer became more refined starting in the 1600s and 1700s, with hops emerging as the primary spice due to their bacteriostatic properties, which help keep beer fresh and provide a clean bitterness. This is akin to how gentian root is used in cocktails to impart bitterness. Hops have dominated beer-making for similar reasons.

However, hops are just one piece of the puzzle. The variety and treatment of malts are equally crucial. Just as wine grapes have distinct flavors based on their growing regions, barley also varies in flavor depending on its geography. However, most people may not easily distinguish between different malt types, much like how an average person might struggle to differentiate between Chardonnay and Pinot Grigio unless the difference is very pronounced, like with Riesling.

For example, Maris Otter malt, developed in the 1950s and 1960s, imparts a deep flavor profile to beer, making it quite different from a beer brewed with a German malt intended for Pilsners. Maris Otter contributes rich, toasty flavors that are not suitable for a lighter beer like Budweiser, which aims for a clean, refreshing taste with minimal aftertaste.

When selecting ingredients, we focus on achieving specific outcomes, such as flavor or color. The appearance of a beverage can influence how its perceived taste; a red drink might evoke different expectations than the same liquid in a black container.

Roasted ingredients, like malts or coffee beans, add layers of complexity, including caramelized notes and bitterness. The degree of roasting can dramatically affect the flavor, as with coffee, where more roasting increases bitterness.

Cultural exposure also affects our perception of flavors. For example, during a visit to Thailand, I encountered a level of astringency I had never experienced before —a dry, plaster-like sensation caused by a chili paste surrounded by bitter melon and leaves. It caused an intense dry sensation in my mouth, reminiscent of plaster. While initially surprising, though not enjoyable to me, I realized that this intense astringency is an essential part of some culinary traditions, and I valued it as part of the culinary experience.

Exploring new flavors can be enlightening, just as the complexity of flavors can also be surprising. For instance, the first time I encountered the variety of bananas in São Paulo, I was amazed by the sheer diversity of banana species. It made me realize how much of what we think we know about flavors might be limited or inaccurate. Many of the vanilla and strawberry flavors we grew up with are often artificial, and recognizing this can change our perception and can feel like a revelation.

In brewing, we strive to balance familiarity with novelty. Our goal is to create beers that provide a familiar and comforting base while introducing something new to intrigue the drinker. It’s essential to accept that not everyone will love every creation. Embracing this diversity of tastes is part of the creative process, whether in brewing, cooking, or any other artistic endeavor. Most people will enjoy most of what you make but accepting that not everyone will appreciate everything is part of the journey.

As one of humanity’s oldest beverages, there is a rich history of incorporating aromatic plants in beer to enhance its flavor, aroma, and preservation. Herbs, spices, and flowers that held cultural or medicinal significance were added. How are plants used in brewing today for both flavor and function?

While hops remain the primary spice in beer, the craft brewing movement has sparked a resurgence of interest in other ingredients that have historically flavored beer. Today, brewers are experimenting with a diverse range of plants, spices, and other flavoring agents. For instance, hibiscus flowers can add a unique flavor, vibrant color, and a touch of acidity to beer.

Historically, using ingredients beyond the traditional barley malt, hops, yeast, and water required brewers to list them on the label or report them to alcohol regulatory authorities. However, modern regulations have become more flexible. Today, many beers are infused with ingredients like coffee, spices, and roots, and as long as these ingredients are generally recognized as safe, there is no need to list them on the label unless they are known allergens.

Brewers now have access to a vast array of flavors, allowing them to draw on historical practices while also innovating. Ingredients such as yarrow, which was commonly used in the UK before hops became widespread in the 1600s and 1700s, is making a comeback. Traditionally, there was a clear distinction in England between “beer” and “ale.” Ale was made without hops, while beer included them. Today, the term “beer” is used broadly to describe both ales and lagers, but the historical difference primarily lies in the flavoring agents used.

This blending of the old and new allows brewers to create unique and exciting beers that honor tradition while pushing the boundaries of what beer can be.

Can you delve deeper into the significance of hops plants, how it’s cultivated and regulated, and why they remain essential in brewing?

Hops are indeed a vital component of beer. They are also the closest botanical relatives to cannabis. They are a vine, often trellised, that can grow 15 to 20 feet tall. The part of the hop used in brewing isn’t technically a flower but a bract, similar to the showy parts of a dogwood flower. The key element lies at the base of these bracts—lupulin, a yellowish powder produced by glands within the hop cones. Lupulin contains essential acids, primarily alpha, and beta acids, which contribute to the characteristic bitterness of beer In addition to these acids, hops contain a wide range of aromatic compounds, including myrcene, linalool, and geraniol. These compounds can evoke a variety of scents, such as floral or citrus notes.

Beyond bitterness, hops are prized for their aromatic compounds, including myrcene, linalool, and geraniol. These compounds impart a wide range of scents, from floral and citrusy to more pungent and earthy notes.

Interestingly, in the Western United States, a term called “dank” was used to describe a specific hop aroma that includes sulfur compounds reminiscent of garlic, onions, and marijuana. Regions like Colorado, where marijuana was popular, embraced this dank character in their beers. This created a regional preference: Western brewers often favored the pungent, earthy, skunky aromas, while Eastern brewers preferred clean, floral, and citrusy notes.

The flavor profile of hops is influenced not only by their variety and growing conditions but also by the timing of their harvest. The longer hops stay on the vine, the more dank character they develop. As a result, hop growers would sometimes pick hops at different times for different brewers: early for those seeking clean, floral flavors and later for those preferring a dank, earthy character. This way, brewers across the country could get the hop characteristics they desired.

Hops are rigorously regulated, particularly in regions where they are cultivated on a large scale, such as the Pacific Northwest in the United States. This regulation ensures that brewers receive a product that meets specific standards, allowing them to create the distinctive flavors and aromas that make each beer unique. The versatility of the hops plant in influencing a beer’s flavor profile makes it an irreplaceable ingredient in the brewing process.

Gayil Nalls, Ph.D., is the creator of World Sensorium and founder of the World Sensorium/Conservancy. She explores how plants and humans shape each other’s story. 

Photographs by Gayil Nalls