The Botany of Beer

It’s no secret that St. Louis is one of the best places to be if you find yourself with a hankering for beer. Starting this July at Garden Party Lights, the Garden joins in the fun with a biergarten that’s open through the rosy glow of summer evenings. But even in the midst of a botanical garden, it’s easy to forget that your beer begins with plants. As craft breweries become more popular, there’s been a growing interest in the specific plants and processes that go into a good beer.

An evening at our biergarten. Photo by Mary Lou Olson.

Brewing beer has been a matter of interest for ages; some of the earliest records we have of writing have to do with the buying, selling, and brewing of beer. Of course, in the early days of brewing, the craft was not about inventing a new flavor profile for a limited time offering; it was more about perfecting the basics and cultivating the plants that went into it.

According to “beer archaeologist” Patrick McGovern, the beer of ancient times isn’t much different than the beer we drink today. Back then, beer was so poorly filtered that it inspired the invention of the straw—this way, you could avoid large chunks of bread or herbs floating in the drink. Other than that, it hasn’t changed much. The plants that we use in beer production have stayed consistent for a reason; their unique characteristics make them the perfect candidates for beer.


In her book, The Drunken Botanist, Amy Stewart writes “The oldest domesticated living organism is not a horse or a chicken, nor is it corn or wheat. It is a wild single-celled, asexual creature capable of preserving food, making bread rise, and fermenting drinks. It is yeast.”

Yeast is actually neither a plant nor an animal—it’s part of the fungus family. Yeast eats sugar and leaves behind waste in the form of ethyl alcohol and carbon dioxide; thus the intoxicating and bubbly nature of beer. Yeast can’t live in a high concentration of its own waste—much like we wouldn’t be happy and healthy living in a sewage plant. So, before distillation was invented, ABV didn’t get much stronger than beer.

Fest of Ale, the Garden’s annual beer festival, took place in May this year. Photo by Kat Niehaus.

To produce the alcohol, there has to be sugar for the yeast to feed on. That’s where the other plants come in. Grain plants usually keep their sugar stored as starch to give to their seeds. When the new seeds germinate, they will depend on that sugar until they grow and can get their own food from photosynthesis. If you get the grains wet, the germination process will be initiated, thus starting the process of converting the starch to sugar. That process is called malting. Once the plants release their sugars, the yeast has something to feed on so that the fermentation process can begin. 


Barley was born to be beer. Most grains are somewhat reluctant to give up their sugars, but barley is the happy exception to this rule. Compared to other grains, it has more of the enzymes that convert starch to sugar, which makes it the easiest to ferment. Its popularity is also aided by its hardiness; barley started in the Middle East, but it flourished wherever it went because it isn’t bothered by cold, drought, or bad soil.

The enthusiasm for beer meant a growing desire to perfect the process, which led to early cultivation of barley. Barley plants tend to drop their seeds right around when the seeds are ready to germinate. This makes them a little harder to collect as they fall to the ground and scatter. But brewers noticed that, by some genetic mutation, some plants tended to hold onto their seeds. It was much easier to collect the seeds when they were still clinging to the plant. Naturally, the seeds from these late-clinging plants were the ones that were planted for future crops and distributed around the world.

Barley and Sorghum from Tibet on display in a past exhibit. Photo by Tom Incrocci.

The joys of drinking beer did not go unappreciated as it spread. According to the Ancient History Encyclopedia, “human beings, after taking care of their immediate needs of food, shelter, and rudimentary laws, will then pursue the creation of some type of intoxicant.” The first beer ever brewed was made in Mesopotamia. There it was as cherished, respected, and frequently consumed as daily bread. The very first brewers were women who were considered priestesses of Ninkasi, the Sumerian goddess of beer, whose praises were sung with great enthusiasm by all:

You are the one who handles the dough [and] with a big shovel,
Mixing in a pit, the bappir with sweet aromatics…

…Ninkasi, you are the one who pours out the filtered beer of the collector vat,
It is [like] the onrush of Tigris and Euphrates.

Read the rest of the hymn here.


Sorghum is far from the most popular choice for brewing beer, but it’s an interesting plant nonetheless. Unlike most other grains in agriculture, sorghum does not contain gluten, which is the ingredient that gives bread its naturally doughy texture. In modern times, we have ways of substituting or replicating that, but historically speaking, lack of gluten would have just been a recipe for very bad bread.

Since it isn’t ideal for food, it never caught on and has not been widely cultivated. However, sorghum is an extremely hardy, heat resistant plant and has sometimes functioned as the saving grace during times of drought and famine. It originated in northeastern Africa and has experienced popularity in a variety of hot, dry climates, including India, Southeast Asia, and, at one point, Kansas.

A sorghum specimen from the Garden’s herbarium.

According to the Kansas State Historical Society, there was a point in time when people went crazy for Sorghum. In the early 1900s, Kansas experienced a number of droughts that made corn an impossibility, but they found that sorghum would produce full crops in spite of the droughts. For years it was the primary grain of the region. In Butler County, it was declared “The Queen of the Prairie,” and in 1911 an annual carnival was started in its honor. Sorghum was so beloved by Kansas residents that the carnival, held in a town of 3,000 people, drew 20,000 to town for the festivities.

As the droughts faded from memory, so did the veneration of sorghum. Production of the crop began to decline in 1930. Today, sorghum has the potential to regain some of its former glory. Lack of gluten–historically the reason it has never been a preferred plant—is now its claim to fame. Sorghum is becoming a popular substitute for barley because it does not contain gluten, so it can be used to create alternative beers for consumers with Celiac disease or other gluten intolerances.


Of all the plants that are used to flavor beer, perhaps none is more famous than hops. Hops can be a challenge to grow in temperate zones because they require about 13 hours of sunlight. Only the female plants are useful to brewers—their cones are what produce that familiar flavor. (Check out our previous post to read more about the plant’s botany in detail.)

An 18thcentury illustration of hops from Johann Wilhelm Weinmann’s Phytanthoza iconographia. Photo from the Missouri Botanical Garden’s Peter H. Raven Library.

It’s hard to say exactly when the use of hops was introduced to the beer world, but one ancient Finnish Saga called Kalevala—which spends more time detailing the creation of beer than the creation of the world–tells a fascinating version of the story: In Kalevala, a brewer named Osmata is trying to create an especially good beer for a wedding celebration. With the help of a bee who flies away in search of a special ingredient and returns with hops, she creates the delicious brew she was aiming for. Her success is honored with an ode to beer that still rings true to any beer-drinker today:

“Great indeed the reputation  
Of the ancient beer of Kalew,  
Said to make the feeble hardy,  
Famed to dry the tears of women,  
Famed to cheer the broken-hearted,  
Make the aged young and supple,  
Make the timid brave and mighty,  
Make the brave men ever braver,  
Fill the heart with joy and gladness,  
Fill the mind with wisdom-sayings,  
Fill the tongue with ancient legends,  
Only makes the fool more foolish.”

The next time you enjoy a beer, you might think to sing Osmata’s praises too. Don’t forget check out Garden Party Lights, where you can enjoy a Garden sunset along with your beer—a drink with a history as ancient as humans’ first domestication of plants. You know what they say: if it ain’t broke, don’t fix it.

Kristina DeYong
Digital Media Specialist

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